Two New Xylanases with Different Substrate Specificities from the Human Gut Bacterium Bacteroides intestinalis DSM 17393

Handle URI:
http://hdl.handle.net/10754/554126
Title:
Two New Xylanases with Different Substrate Specificities from the Human Gut Bacterium Bacteroides intestinalis DSM 17393
Authors:
Hong, Pei-Ying ( 0000-0002-4474-6600 ) ; Iakiviak, M.; Dodd, D.; Zhang, M.; Mackie, R. I.; Cann, I.
Abstract:
Xylan is an abundant plant cell wall polysaccharide and is a dominant component of dietary fiber. Bacteria in the distal human gastrointestinal tract produce xylanase enzymes to initiate the degradation of this complex heteropolymer. These xylanases typically derive from glycoside hydrolase (GH) families 10 and 11; however, analysis of the genome sequence of the xylan-degrading human gut bacterium Bacteroides intestinalis DSM 17393 revealed the presence of two putative GH8 xylanases. In the current study, we demonstrate that the two genes encode enzymes that differ in activity. The xyn8A gene encodes an endoxylanase (Xyn8A), and rex8A encodes a reducing-end xylose-releasing exo-oligoxylanase (Rex8A). Xyn8A hydrolyzed both xylopentaose (X5) and xylohexaose (X6) to a mixture of xylobiose (X2) and xylotriose (X3), while Rex8A hydrolyzed X3 through X6 to a mixture of xylose (X1) and X2. Moreover, rex8A is located downstream of a GH3 gene (xyl3A) that was demonstrated to exhibit β-xylosidase activity and would be able to further hydrolyze X2 to X1. Mutational analyses of putative active site residues of both Xyn8A and Rex8A confirm their importance in catalysis by these enzymes. Recent genome sequences of gut bacteria reveal an increase in GH8 Rex enzymes, especially among the Bacteroidetes, indicating that these genes contribute to xylan utilization in the human gut.
KAUST Department:
Environmental Science and Engineering Program; Water Desalination and Reuse Research Center (WDRC)
Citation:
Two New Xylanases with Different Substrate Specificities from the Human Gut Bacterium Bacteroides intestinalis DSM 17393 2014, 80 (7):2084 Applied and Environmental Microbiology
Journal:
Applied and Environmental Microbiology
Issue Date:
24-Jan-2014
DOI:
10.1128/AEM.03176-13
PubMed ID:
24463968
PubMed Central ID:
PMC3993143
Type:
Article
ISSN:
0099-2240
Additional Links:
http://aem.asm.org/cgi/doi/10.1128/AEM.03176-13
Appears in Collections:
Articles; Environmental Science and Engineering Program; Water Desalination and Reuse Research Center (WDRC); Water Desalination and Reuse Research Center (WDRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorHong, Pei-Yingen
dc.contributor.authorIakiviak, M.en
dc.contributor.authorDodd, D.en
dc.contributor.authorZhang, M.en
dc.contributor.authorMackie, R. I.en
dc.contributor.authorCann, I.en
dc.date.accessioned2015-05-18T21:57:33Zen
dc.date.available2015-05-18T21:57:33Zen
dc.date.issued2014-01-24en
dc.identifier.citationTwo New Xylanases with Different Substrate Specificities from the Human Gut Bacterium Bacteroides intestinalis DSM 17393 2014, 80 (7):2084 Applied and Environmental Microbiologyen
dc.identifier.issn0099-2240en
dc.identifier.pmid24463968en
dc.identifier.doi10.1128/AEM.03176-13en
dc.identifier.urihttp://hdl.handle.net/10754/554126en
dc.description.abstractXylan is an abundant plant cell wall polysaccharide and is a dominant component of dietary fiber. Bacteria in the distal human gastrointestinal tract produce xylanase enzymes to initiate the degradation of this complex heteropolymer. These xylanases typically derive from glycoside hydrolase (GH) families 10 and 11; however, analysis of the genome sequence of the xylan-degrading human gut bacterium Bacteroides intestinalis DSM 17393 revealed the presence of two putative GH8 xylanases. In the current study, we demonstrate that the two genes encode enzymes that differ in activity. The xyn8A gene encodes an endoxylanase (Xyn8A), and rex8A encodes a reducing-end xylose-releasing exo-oligoxylanase (Rex8A). Xyn8A hydrolyzed both xylopentaose (X5) and xylohexaose (X6) to a mixture of xylobiose (X2) and xylotriose (X3), while Rex8A hydrolyzed X3 through X6 to a mixture of xylose (X1) and X2. Moreover, rex8A is located downstream of a GH3 gene (xyl3A) that was demonstrated to exhibit β-xylosidase activity and would be able to further hydrolyze X2 to X1. Mutational analyses of putative active site residues of both Xyn8A and Rex8A confirm their importance in catalysis by these enzymes. Recent genome sequences of gut bacteria reveal an increase in GH8 Rex enzymes, especially among the Bacteroidetes, indicating that these genes contribute to xylan utilization in the human gut.en
dc.relation.urlhttp://aem.asm.org/cgi/doi/10.1128/AEM.03176-13en
dc.rightsArchived with thanks to Applied and Environmental Microbiologyen
dc.titleTwo New Xylanases with Different Substrate Specificities from the Human Gut Bacterium Bacteroides intestinalis DSM 17393en
dc.typeArticleen
dc.contributor.departmentEnvironmental Science and Engineering Programen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.identifier.journalApplied and Environmental Microbiologyen
dc.identifier.pmcidPMC3993143en
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USAen
dc.contributor.institutionInstitute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USAen
dc.contributor.institutionDepartment of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USAen
dc.contributor.institutionSchool of Life Science, East China Normal University, Shanghai, Chinaen
dc.contributor.institutionDepartment of Pathology, Stanford University School of Medicine, Stanford, California, USA.en
kaust.authorHong, Pei-Yingen
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