Displaying publications 1 - 20 of 34 in total

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  1. Antonova I, Gridnyev O, Galchinskaya V
    Wiad Lek, 2022;75(11 pt 2):2779-2784.
    PMID: 36591768 DOI: 10.36740/WLek202211211
    OBJECTIVE: The aim: The aim of the present study was to establish a link between polymorphic variants of the microsomal epoxide hydrolase gene and the severity of COPD in patients with COPD and coronary heart disease.

    PATIENTS AND METHODS: Materials and methods: The study included 128 patients with COPD and IHD, who were divided into two groups: group 1 included 72 patients with in¬frequent exacerbations of COPD (0-1 per year) and group 2 included 56 patients with frequent exacerbations of COPD (exacerbation of COPD ≥2 per year). The control groups consisted of 15 smokers without COPD and IHD, 11 practically healthy non-smokers and 11 patients with IHD who do not smoke. All patients underwent DNA isolation and purification, followed by determination of the Tyr113His polymorphism of the EPHX1 microsomal epoxide hydrolase gene (rs1051740).

    RESULTS: Results: There was a significant association of the carriage of the CC genotype of the EPHX1 gene in patients with COPD and IHD (RO = 21.326 [95.0% CI 4.217-107.846], p <0.001) with a more severe course of COPD compared with the TT genotype of the EPHX1 gene.

    CONCLUSION: Conclusions: Patients with COPD and coronary heart disease who were carriers of a homozygous variant СС of the EPHX1 gene have a reliable association with a more severe course of COPD with frequent exacerbations (higher class according to GOLD classification and more severe symptoms of COPD according to the СAT questionnaire).

    Matched MeSH terms: Hydrolases/genetics
  2. Oyewusi HA, Akinyede KA, Abdul Wahab R, Huyop F
    J Biomol Struct Dyn, 2023 Jan;41(1):319-335.
    PMID: 34854349 DOI: 10.1080/07391102.2021.2006085
    Microbial-assisted removal of natural or synthetic pollutants is the prevailing green, low-cost technology to treat polluted environments. However, the challenge with enzyme-assisted bioremediation is the laborious nature of dehalogenase-producing microorganisms' bioprospecting. This bottleneck could be circumvented by in-silico analysis of certain microorganisms' whole-genome sequences to predict their protein functions and enzyme versatility for improved biotechnological applications. Herein, this study performed structural analysis on a dehalogenase (DehHsAAD6) from the genome of Halomonas smyrnensis AAD6 by molecular docking and molecular dynamic (MD) simulations. Other bioinformatics tools were also employed to identify substrate preference (haloacids and haloacetates) of the DehHsAAD6. The DehHsAAD6 preferentially degraded haloacids and haloacetates (-3.2-4.8 kcal/mol) and which formed three hydrogen bonds with Tyr12, Lys46, and Asp182. MD simulations data revealed the higher stability of DehHsAAD6-haloacid- (RMSD 0.22-0.3 nm) and DehHsAAD6-haloacetates (RMSF 0.05-0.14 nm) complexes, with the DehHsAAD6-L-2CP complex being the most stable. The detail of molecular docking calculations ranked complexes with the lowest binding free energies as: DehHsAAD6-L-2CP complex (-4.8 kcal/mol) = DehHsAAD6-MCA (-4.8 kcal/mol) < DehHsAAD6-TCA (-4.5 kcal/mol) < DehHsAAD6-2,3-DCP (-4.1 kcal/mol) < DehHsAAD6-D-2CP (-3.9 kcal/mol) < DehHsAAD6-2,2-DCP (-3.5 kcal/mol) < DehHsAAD6-3CP (-3.2 kcal/mol). In a nutshell, the study findings offer valuable perceptions into the elucidation of possible reaction mechanisms of dehalogenases for extended substrate specificity and higher catalytic activity.Communicated by Ramaswamy H. Sarma.
    Matched MeSH terms: Hydrolases/genetics
  3. Oyewusi HA, Wahab RA, Huyop F
    Mol Biol Rep, 2021 Mar;48(3):2687-2701.
    PMID: 33650078 DOI: 10.1007/s11033-021-06239-7
    An integral approach to decoding both culturable and uncultured microorganisms' metabolic activity involves the whole genome sequencing (WGS) of individual/complex microbial communities. WGS of culturable microbes, amplicon sequencing, metagenomics, and single-cell genome analysis are selective techniques integrating genetic information and biochemical mechanisms. These approaches transform microbial biotechnology into a quick and high-throughput culture-independent evaluation and exploit pollutant-degrading microbes. They are windows into enzyme regulatory bioremediation pathways (i.e., dehalogenase) and the complete bioremediation process of organohalide pollutants. While the genome sequencing technique is gaining the scientific community's interest, it is still in its infancy in the field of pollutant bioremediation. The techniques are becoming increasingly helpful in unraveling and predicting the enzyme structure and explore metabolic and biodegradation capabilities.
    Matched MeSH terms: Hydrolases/genetics
  4. Zainuddin N, Jaafar H, Isa MN, Abdullah JM
    Med J Malaysia, 2004 Oct;59(4):468-79.
    PMID: 15779579
    Loss of heterozygosity (LOH) on several loci and mutations on PTEN tumor suppressor gene (10q23.3) occur frequently in sporadic gliomas. We have performed polymerase chain reaction (PCR)-LOH analysis using microsatellite markers and single-stranded conformational polymorphism (SSCP) analysis to determine the incidence of allelic losses on chromosome 10q, 9p, 17p and 13q and mutations of exons 5, 6 and 8 of the PTEN gene in malignant gliomas. Twelve of 23 (52.2%) malignant glioma cases showed allelic losses whereas 7 of 23, (30.4%) samples showed aberrant band patterns and mutations of the PTEN gene. Four of these cases showed LOH on 10q23 and mutations of the PTEN gene. The data on LOH indicated the involvement of different genes in gliomagenesis whereas mutations of the PTEN gene indicated the role of PTEN tumor suppressor gene in the progression of glioma in Malay population.
    Matched MeSH terms: Phosphoric Monoester Hydrolases/genetics*
  5. Shakiba MH, Ali MS, Rahman RN, Salleh AB, Leow TC
    Extremophiles, 2016 Jan;20(1):44-55.
    PMID: 26475626 DOI: 10.1007/s00792-015-0796-4
    The gene encoding for a novel cold-adapted enzyme from family II of bacterial classification (GDSL family) was cloned from the genomic DNA of Photobacterium sp. strain J15 in an Escherichia coli system, yielding a recombinant 36 kDa J15 GDSL esterase which was purified in two steps with a final yield and purification of 38.6 and 15.3 respectively. Characterization of the biochemical properties showed the J15 GDSL esterase had maximum activity at 20 °C and pH 8.0, was stable at 10 °C for 3 h and retained 50 % of its activity after a 6 h incubation at 10 °C. The enzyme was activated by Tween-20, -60 and Triton-X100 and inhibited by 1 mM Sodium dodecyl sulphate (SDS), while β-mercaptoethanol and Dithiothreitol (DTT) enhanced activity by 4.3 and 5.4 fold respectively. These results showed the J15 GDSL esterase was a novel cold-adapted enzyme from family II of lipolytic enzymes. A structural model constructed using autotransporter EstA from Pseudomonas aeruginosa as a template revealed the presence of a typical catalytic triad consisting of a serine, aspartate, and histidine which was verified with site directed mutagenesis on active serine.
    Matched MeSH terms: Carboxylic Ester Hydrolases/genetics
  6. Thevarajoo S, Selvaratnam C, Chan KG, Goh KM, Chong CS
    Mar Genomics, 2015 Oct;23:49-50.
    PMID: 25957696 DOI: 10.1016/j.margen.2015.04.009
    Type strain Vitellibacter vladivostokensis KMM 3516(T) (=NBRC 16718(T)) belongs to the phylum Cytophaga-Flavobacterium-Bacteroides. To date, no genomes of the Vitellibacter spp. have been reported, and their metabolic pathways are unknown. This study reports the draft genome sequence of V. vladivostokensis. Moreover, mining of genes associated with proteolytic enzymes was performed to provide insights for further enzyme characterization.
    Matched MeSH terms: Peptide Hydrolases/genetics
  7. Hamid AA, Hamid TH, Wahab RA, Omar MS, Huyop F
    PLoS One, 2015;10(3):e0121687.
    PMID: 25816329 DOI: 10.1371/journal.pone.0121687
    The non-stereospecific α-haloalkanoic acid dehalogenase E (DehE) degrades many halogenated compounds but is ineffective against β-halogenated compounds such as 3-chloropropionic acid (3CP). Using molecular dynamics (MD) simulations and site-directed mutagenesis we show here that introducing the mutation S188V into DehE improves substrate specificity towards 3CP. MD simulations showed that residues W34, F37, and S188 of DehE were crucial for substrate binding. DehE showed strong binding ability for D-2-chloropropionic acid (D-2CP) and L-2-chloropropionic acid (L-2CP) but less affinity for 3CP. This reduced affinity was attributed to weak hydrogen bonding between 3CP and residue S188, as the carboxylate of 3CP forms rapidly interconverting hydrogen bonds with the backbone amide and side chain hydroxyl group of S188. By replacing S188 with a valine residue, we reduced the inter-molecular distance and stabilised bonding of the carboxylate of 3CP to hydrogens of the substrate-binding residues. Therefore, the S188V can act on 3CP, although its affinity is less strong than for D-2CP and L-2CP as assessed by Km. This successful alteration of DehE substrate specificity may promote the application of protein engineering strategies to other dehalogenases, thereby generating valuable tools for future bioremediation technologies.
    Matched MeSH terms: Hydrolases/genetics*
  8. Tan SG, Teng YS, Ganesan J, Lau KY, Lie-Injo LE
    Hum Genet, 1979 Jul 18;49(3):349-53.
    PMID: 289626
    Kadazans, the largest indigenous group in Sabah, northern Borneo, were surveyed for glyoxalase I, phosphoglucomutase I, red cell acid phosphatase, esterase D, adenosine deaminase, soluble glutamate pyruvate transaminase, soluble glutamate oxaloacetate transaminase, 6-phosphogluconate dehydrogenase, uridine monophosphate kinase, adenylate kinase, peptidase B and D, superoxide dismutase, C5, group specific component, haptoglobin and transferrin. Kadazans were found to be polymorphic for GLO I, PGM I, RCAP, esterase D, ADA, s-Gpt, 6PGD, UMPK, Gc, C5, haptoglobin and peptidase B. Rare variants were found for transferrin and peptidase D. No variant was found for s-Got, SOD and AK.
    Matched MeSH terms: Peptide Hydrolases/genetics
  9. Haragannavar VC, Tegginamani AS, Raju S, Kudva S, Peter CD, Shruthi DK
    Indian J Pathol Microbiol, 2019 2 2;62(1):3-6.
    PMID: 30706851 DOI: 10.4103/IJPM.IJPM_403_18
    Background: FHIT (Fragile histidine triad) a member of tumor suppressor family, has been extensively studied in many solid tumors including head and neck squamous cell carcinoma. Among all head and neck cyst and tumors odontogenic lesions account approximately 3%-9%. The molecular pathogenesis of these lesions is less explored. Defects in cell cycle regulators and tumor suppressor genes could result in the development of odontogenic cyst and tumors. Hence, we aimed to determine the significant role of a tumor suppressor gene FHIT in most commonly occurring odontogenic lesions mainly ameloblastoma, odontogenic keratocyst and dentigerous cyst.

    Subjects and Methods: Immunohistochemical analysis of FHIT was done in ameloblastoma, odontogenic keratocyst, dentigerous cyst and dental follicle. Interpretation of the stained slides were done using standard scoring criteria by two pathologist. The results were subjected for statistical analysis.

    Results: Expression of FHIT varied among the groups, with highest negative expression in ameloblastoma 44.4% followed by odontogenic keratocyst 14% and 100%positive expression was seen in dentigerous cyst. The expression levels between the groups were statistically insignificant.

    Conclusion: The varied expression or negative expression of FHIT could be considered as an indicator for aggressive behavior and transformation of preneoplastic/cystic epithelium.

    Matched MeSH terms: Acid Anhydride Hydrolases/genetics*
  10. Abdul Karim MH, Lam MQ, Chen SJ, Yahya A, Shahir S, Shamsir MS, et al.
    Arch Microbiol, 2020 Nov;202(9):2591-2597.
    PMID: 32607725 DOI: 10.1007/s00203-020-01967-z
    To date, the genus Parvularcula consists of 6 species and no potential application of this genus was reported. Current study presents the genome sequence of Parvularcula flava strain NH6-79 T and its cellulolytic enzyme analysis. The assembled draft genome of strain NH6-79 T consists of 9 contigs and 7 scaffolds with 3.68 Mbp in size and GC content of 59.87%. From a total of 3,465 genes predicted, 96 of them are annotated as glycoside hydrolases (GHs). Within these GHs, 20 encoded genes are related to cellulosic biomass degradation, including 12 endoglucanases (5 GH10, 4 GH5, and 3 GH51), 2 exoglucanases (GH9) and 6 β-glucosidases (GH3). In addition, highest relative enzyme activities (endoglucanase, exoglucanase, and β-glucosidase) were observed at 27th hour when the strain was cultured in the carboxymethyl cellulose/Avicel®-containing medium for 45 h. The combination of genome analysis with experimental studies indicated the ability of strain NH6-79 T to produce extracellular endoglucanase, exoglucanase, and β-glucosidase. These findings suggest the potential of Parvularcula flava strain NH6-79 T in cellulose-containing biomass degradation and that the strain could be used in cellulosic biorefining process.
    Matched MeSH terms: Glycoside Hydrolases/genetics*
  11. Adamu A, Abdul Wahab R, Aliyu F, Abdul Razak FI, Mienda BS, Shamsir MS, et al.
    J Mol Graph Model, 2019 11;92:131-139.
    PMID: 31352207 DOI: 10.1016/j.jmgm.2019.07.012
    Dehalogenases continue to garner interest of the scientific community due to their potential applications in bioremediation of halogen-contaminated environment and in synthesis of various industrially relevant products. Example of such enzymes is DehL, an L-2-haloacid dehalogenase (EC 3.8.1.2) from Rhizobium sp. RC1 that catalyses the specific cleavage of halide ion from L-2-halocarboxylic acids to produce the corresponding D-2-hydroxycarboxylic acids. Recently, the catalytic residues of DehL have been identified and its catalytic mechanism has been fully elucidated. However, the enantiospecificity determinants of the enzyme remain unclear. This information alongside a well-defined catalytic mechanism are required for rational engineering of DehL for substrate enantiospecificity. Therefore, using quantum mechanics/molecular mechanics and molecular mechanics Poisson-Boltzmann surface area calculations, the current study theoretically investigated the molecular basis of DehL enantiospecificity. The study found that R51L mutation cancelled out the dehalogenation activity of DehL towards it natural substrate, L-2-chloropropionate. The M48R mutation, however introduced a new activity towards D-2-chloropropionate, conveying the possibility of inverting the enantiospecificity of DehL from L-to d-enantiomer with a minimum of two simultaneous mutations. The findings presented here will play important role in the rational design of DehL dehalogenase for improving substrate utility.
    Matched MeSH terms: Hydrolases/genetics
  12. Hamid AA, Hamid TH, Wahab RA, Huyop F
    J Basic Microbiol, 2015 Mar;55(3):324-30.
    PMID: 25727054 DOI: 10.1002/jobm.201570031
    The non-stereospecific α-haloalkanoic acid dehalogenase DehE from Rhizobium sp. RC1 catalyzes the removal of the halide from α-haloalkanoic acid D,L-stereoisomers and, by doing so, converts them into hydroxyalkanoic acid L,D-stereoisomers, respectively. DehE has been extensively studied to determine its potential to act as a bioremediation agent, but its structure/function relationship has not been characterized. For this study, we explored the functional relevance of several putative active-site amino acids by site-specific mutagenesis. Ten active-site residues were mutated individually, and the dehalogenase activity of each of the 10 resulting mutants in soluble cell lysates against D- and L-2-chloropropionic acid was assessed. Interestingly, the mutants W34→A,F37→A, and S188→A had diminished activity, suggesting that these residues are functionally relevant. Notably, the D189→N mutant had no activity, which strongly implies that it is a catalytically important residue. Given our data, we propose a dehalogenation mechanism for DehE, which is the same as that suggested for other non-stereospecific α-haloalkanoic acid dehalogenases. To the best of our knowledge, this is the first report detailing a functional aspect for DehE, and our results could help pave the way for the bioengineering of haloalkanoic acid dehalogenases with improved catalytic properties.
    Matched MeSH terms: Hydrolases/genetics
  13. Rai KM, Balasubramanian VK, Welker CM, Pang M, Hii MM, Mendu V
    BMC Plant Biol, 2015;15:187.
    PMID: 26232118 DOI: 10.1186/s12870-015-0576-4
    The plant cell wall serves as a primary barrier against pathogen invasion. The success of a plant pathogen largely depends on its ability to overcome this barrier. During the infection process, plant parasitic nematodes secrete cell wall degrading enzymes (CWDEs) apart from piercing with their stylet, a sharp and hard mouthpart used for successful infection. CWDEs typically consist of cellulases, hemicellulases, and pectinases, which help the nematode to infect and establish the feeding structure or form a cyst. The study of nematode cell wall degrading enzymes not only enhance our understanding of the interaction between nematodes and their host, but also provides information on a novel source of enzymes for their potential use in biomass based biofuel/bioproduct industries. Although there is comprehensive information available on genome wide analysis of CWDEs for bacteria, fungi, termites and plants, but no comprehensive information available for plant pathogenic nematodes. Herein we have performed a genome wide analysis of CWDEs from the genome sequenced phyto pathogenic nematode species and developed a comprehensive publicly available database.
    Matched MeSH terms: Glycoside Hydrolases/genetics
  14. Raftari M, Ghafourian S, Abu Bakar F
    J Appl Microbiol, 2017 Apr;122(4):1009-1019.
    PMID: 28028882 DOI: 10.1111/jam.13388
    AIMS: This study was an attempt to create a novel milk clotting procedure using a recombinant bacterium capable of milk coagulation.

    METHODS AND RESULTS: The Rhizomucor pusillus proteinase (RPP) gene was sub-cloned into a pALF expression vector. The recombinant pALF-RPP vector was then electro-transferred into Lactococcus lactis. Finally, the milk coagulation ability of recombinant L. lactis carrying a RPP gene was evaluated. Nucleotide sequencing of DNA insertion from the clone revealed that the RPP activity corresponded to an open reading frame consisting of 1218 bp coding for a 43·45 kDa RPP protein. The RPP protein assay results indicated that the highest RPP enzyme expression with 870 Soxhlet units (SU) per ml and 7914 SU/OD were obtained for cultures which were incubated at pH 5·5 and 30°C. Interestingly, milk coagulation was observed after 205 min of inoculating milk with recombinant L. lactis carrying the RPP gene.

    CONCLUSION: The recombinant L. lactis carrying RPP gene has the ability to function as a starter culture for acidifying and subsequently coagulating milk by producing RPP as a milk coagulant agent.

    SIGNIFICANCE AND IMPACT OF THE STUDY: Creating a recombinant starter culture bacterium that is able to coagulate milk. It is significant because the recombinant L. lactis has the ability to work as a starter culture and milk coagulation agent.

    Matched MeSH terms: Peptide Hydrolases/genetics*
  15. Zarinah KH, Abdullah F, Tan SG
    Ann Hum Biol, 1984 11 1;11(6):533-6.
    PMID: 6084457
    Three genetic markers, red-cell UMPK, PGP and serum AMY2 were investigated in Malaysians of Malay, Chinese and Indian ancestries using starch-gel and agarose-gel electrophoresis. UMPK was found to be polymorphic in all three races. Variants were observed for PGP in Malays; in Indians it is a polymorphic marker whereas it is monomorphic in Chinese. AMY2 was polymorphic only in Indians. The UMPK1 frequencies in Malays, Chinese and Indians, respectively, are 0.851, 0.880 and 0.942. The PGP1 frequencies are 0.991, 1.000, 0.962, and the AMY1(2) frequencies are 1.000, 1.000 and 0.983.
    Matched MeSH terms: Phosphoric Monoester Hydrolases/genetics*
  16. Tee KK, Pon CK, Kamarulzaman A, Ng KP
    AIDS, 2005 Jan 28;19(2):119-26.
    PMID: 15668536
    OBJECTIVES: To investigate the molecular epidemiology of HIV-1 and to screen for the emergence of intersubtype recombinants in Kuala Lumpur, Malaysia.

    DESIGN: A molecular epidemiology study was conducted among HIV-1 seropositive patients attending the University Malaya Medical Center (UMMC) from July 2003 to June 2004.

    METHODS: Protease (PR) and reverse transcriptase (RT) gene sequences were derived from drug resistance genotyping assay of 100 newly diagnosed or antiretroviral-naive patients. These were phylogenetically analysed to determine the subtypes and recombination breakpoint analyses were performed on intersubtype recombinants to estimate the recombination breakpoint(s).

    RESULTS: CRF01_AE predominated in Kuala Lumpur with 65% in both PR and RT genes. B subtype was detected at 14% and 12% in PR and RT genes, respectively. C subtype was present at 1% in both genes. Overall, the concordance of PR and RT genes in discriminating subtypes/circulating recombinant forms (CRF) was high at 96%. In this study, novel CRF01_AE/B intersubtype recombinants were detected at high prevalence (22%), including those isolates with subtype discordance. Thai variants of CRF01_AE and B subtype were involved in the genesis of these unique recombinant forms (URF). Interestingly, 19 CRF01_AE/B intersubtype recombinant isolates shared similar recombination breakpoints in both PR and RT genes. Several distinct URF were also identified.

    CONCLUSION: PR and RT genes can be utilized for subtype/CRF assessment with high degree of agreement, allowing concurrent surveillance of circulating HIV-1 subtypes with antiretroviral drug resistance genotyping tests. The emergence of highly identical CRF01_AE/B intersubtype recombinants suggests the possibility of the appearance of a new circulating recombinant form in Kuala Lumpur.

    Matched MeSH terms: Peptide Hydrolases/genetics
  17. Chin IS, Abdul Murad AM, Mahadi NM, Nathan S, Abu Bakar FD
    Protein Eng. Des. Sel., 2013 May;26(5):369-75.
    PMID: 23468570 DOI: 10.1093/protein/gzt007
    Cutinase has been ascertained as a biocatalyst for biotechnological and industrial bioprocesses. The Glomerella cingulata cutinase was genetically modified to enhance its enzymatic performance to fulfill industrial requirements. Two sites were selected for mutagenesis with the aim of altering the surface electrostatics as well as removing a potentially deamidation-prone asparagine residue. The N177D cutinase variant was affirmed to be more resilient to temperature increase with a 2.7-fold increase in half-life at 50°C as compared with wild-type enzyme, while, the activity at 25°C is not compromised. Furthermore, the increase in thermal tolerance of this variant is accompanied by an increase in optimal temperature. Another variant, the L172K, however, exhibited higher enzymatic performance towards phenyl ester substrates of longer carbon chain length, yet its thermal stability is inversely affected. In order to restore the thermal stability of L172K, we constructed a L172K/N177D double variant and showed that these two mutations yield an improved variant with enhanced activity towards phenyl ester substrates and enhanced thermal stability. Taken together, our study may provide valuable information for enhancing catalytic performance and thermal stability in future engineering endeavors.
    Matched MeSH terms: Carboxylic Ester Hydrolases/genetics*
  18. Lee LS, Goh KM, Chan CS, Annie Tan GY, Yin WF, Chong CS, et al.
    Microbiologyopen, 2018 12;7(6):e00615.
    PMID: 29602271 DOI: 10.1002/mbo3.615
    The ability of thermophilic microorganisms and their enzymes to decompose biomass have attracted attention due to their quick reaction time, thermostability, and decreased risk of contamination. Exploitation of efficient thermostable glycoside hydrolases (GHs) could accelerate the industrialization of biofuels and biochemicals. However, the full spectrum of thermophiles and their enzymes that are important for biomass degradation at high temperatures have not yet been thoroughly studied. We examined a Malaysian Y-shaped Sungai Klah hot spring located within a wooded area. The fallen foliage that formed a thick layer of biomass bed under the heated water of the Y-shaped Sungai Klah hot spring was an ideal environment for the discovery and analysis of microbial biomass decay communities. We sequenced the hypervariable regions of bacterial and archaeal 16S rRNA genes using total community DNA extracted from the hot spring. Data suggested that 25 phyla, 58 classes, 110 orders, 171 families, and 328 genera inhabited this hot spring. Among the detected genera, members of Acidimicrobium, Aeropyrum, Caldilinea, Caldisphaera, Chloracidobacterium, Chloroflexus, Desulfurobacterium, Fervidobacterium, Geobacillus, Meiothermus, Melioribacter, Methanothermococcus, Methanotorris, Roseiflexus, Thermoanaerobacter, Thermoanaerobacterium, Thermoanaerobaculum, and Thermosipho were the main thermophiles containing various GHs that play an important role in cellulose and hemicellulose breakdown. Collectively, the results suggest that the microbial community in this hot spring represents a good source for isolating efficient biomass degrading thermophiles and thermozymes.
    Matched MeSH terms: Glycoside Hydrolases/genetics
  19. Furusawa G, Lau NS, Suganthi A, Amirul AA
    Microbiologyopen, 2017 02;6(1).
    PMID: 27987272 DOI: 10.1002/mbo3.405
    The agarolytic bacterium Persicobacter sp. CCB-QB2 was isolated from seaweed (genus Ulva) collected from a coastal area of Malaysia. Here, we report a high-quality draft genome sequence for QB2. The Rapid Annotation using Subsystem Technology (RAST) annotation server identified four β-agarases (PdAgaA, PdAgaB, PdAgaC, and PdAgaD) as well as galK, galE, and phosphoglucomutase, which are related to the Leloir pathway. Interestingly, QB2 exhibited a diauxic growth in the presence of two kinds of nutrients, such as tryptone and agar. In cells grown with agar, the profiles of agarase activity and growth rate were very similar. galK, galE, and phosphoglucomutase genes were highly expressed in the second growth phase of diauxic growth, indicating that QB2 cells use galactose hydrolyzed from agar by its agarases and exhibit nutrient prioritization. This is the first report describing diauxic growth for agarolytic bacteria. QB2 is a potential novel model organism for studying diauxic growth in environmental bacteria.
    Matched MeSH terms: Glycoside Hydrolases/genetics*
  20. Jamek SB, Nyffenegger C, Muschiol J, Holck J, Meyer AS, Mikkelsen JD
    Appl Microbiol Biotechnol, 2017 Jun;101(11):4533-4546.
    PMID: 28280871 DOI: 10.1007/s00253-017-8198-4
    Type A chitinases (EC 3.2.1.14), GH family 18, attack chitin ((1 → 4)-2-acetamido-2-deoxy-β-D-glucan) and chito-oligosaccharides from the reducing end to catalyze release of chitobiose (N,N'-diacetylchitobiose) via hydrolytic cleavage of N-acetyl-β-D-glucosaminide (1 → 4)-β-linkages and are thus "exo-chitobiose hydrolases." In this study, the chitinase type A from Serratia marcescens (SmaChiA) was used as a template for identifying two novel exo-chitobiose hydrolase type A enzymes, FbalChi18A and MvarChi18A, originating from the marine organisms Ferrimonas balearica and Microbulbifer variabilis, respectively. Both FbalChi18A and MvarChi18A were recombinantly expressed in Escherichia coli and were confirmed to exert exo-chitobiose hydrolase activity on chito-oligosaccharides, but differed in temperature and pH activity response profiles. Amino acid sequence comparison of the catalytic β/α barrel domain of each of the new enzymes showed individual differences, but ~69% identity of each to that of SmaChiA and highly conserved active site residues. Superposition of a model substrate on 3D structural models of the catalytic domain of the enzymes corroborated exo-chitobiose hydrolase type A activity for FbalChi18A and MvarChi18A, i.e., substrate attack from the reducing end. A main feature of both of the new enzymes was the presence of C-terminal 5/12 type carbohydrate-binding modules (SmaChiA has no C-terminal carbohydrate binding module). These new enzymes may be useful tools for utilization of chitin as an N-acetylglucosamine donor substrate via chitobiose.
    Matched MeSH terms: Hydrolases/genetics*
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