Insights into the Molecular Determinants of Substrate Specificity in Glycoside Hydrolase Family 5 Revealed by the Crystal Structure and Kinetics of Cellvibrio mixtus Mannosidase 5A
| Autor: | Louise E. Tailford, Florence Vincent, Luís M. A. Ferreira, Maria S.J. Centeno, José A. M. Prates, Fernando M. V. Dias, Gavin Pell, Gideon J. Davies, Harry J. Gilbert, Carlos M. G. A. Fontes |
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| Přispěvatelé: | Instituto Superior Técnico, Universidade Técnica de Lisboa, Architecture et fonction des macromolécules biologiques (AFMB), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Newcastle University [Newcastle], Centro de Investigaçao Interdisciplinar em Sanidade Animal (CIISA), Faculdade de Medicina Veterinária-Technical University of Lisbon, Faculdade de Medicina Veterinária, University of York [York, UK], University of Newcastle [Australia] (UoN), Newcastle Upon Tyne Hospitals NHS Foundation Trust, Universidade de Lisboa = University of Lisbon (ULISBOA), NZYTech Genes & Enzymes, University of Newcastle [Callaghan, Australia] (UoN), UK Research & Innovation (UKRI) Biotechnology and Biological Sciences Research Council (BBSRC) BBS/B/05974 B20376, Universidade de Lisboa (ULISBOA) |
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Mannosidase
Stereochemistry Cellvibrio Mannose Biochemistry Catalysis Substrate Specificity 03 medical and health sciences chemistry.chemical_compound Hydrolase Glycoside hydrolase [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry Molecular Biology/Biochemistry [q-bio.BM] Molecular Biology 030304 developmental biology chemistry.chemical_classification 0303 health sciences biology [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry Molecular Biology/Structural Biology [q-bio.BM] Glycoside hydrolase family 5 Hydrolysis 030302 biochemistry & molecular biology beta-Mannosidase Glycosidic bond [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry Molecular Biology/Molecular biology Cell Biology biology.organism_classification [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry Molecular Biology/Biophysics Kinetics Aglycone chemistry Multigene Family Crystallization |
| Zdroj: | Journal of Biological Chemistry Journal of Biological Chemistry, American Society for Biochemistry and Molecular Biology, 2004, 279 (24), pp.25517-25526. ⟨10.1074/jbc.M401647200⟩ Journal of Biological Chemistry, 2004, 279 (24), pp.25517-25526. ⟨10.1074/jbc.m401647200⟩ Journal of Biological Chemistry, American Society for Biochemistry and Molecular Biology, 2004, 279 (24), pp.25517-25526. ⟨10.1074/jbc.m401647200⟩ |
| ISSN: | 0021-9258 1083-351X |
| DOI: | 10.1074/jbc.M401647200⟩ |
| Popis: | The enzymatic hydrolysis of the glycosidic bond is central to numerous biological processes. Glycoside hydrolases, which catalyze these reactions, are grouped into families based on primary sequence similarities. One of the largest glycoside hydrolase families is glycoside hydrolase family 5 (GH5), which contains primarily endo-acting enzymes that hydrolyze beta-mannans and beta-glucans. Here we report the cloning, characterization, and three-dimensional structure of the Cellvibrio mixtus GH5 beta-mannosidase (CmMan5A). This enzyme releases mannose from the nonreducing end of mannooligosaccharides and polysaccharides, an activity not previously observed in this enzyme family. CmMan5A contains a single glycone (-1) and two aglycone (+1 and +2) sugar-binding subsites. The -1 subsite displays absolute specificity for mannose, whereas the +1 subsite does not accommodate galactosyl side chains but will bind weakly to glucose. The +2 subsite is able to bind to decorated mannose residues. CmMan5A displays similar activity against crystalline and amorphous mannans, a property rarely attributed to glycoside hydrolases. The 1.5 A crystal structure reveals that CmMan5A adopts a (beta/alpha)(8) barrel fold, and superimposition with GH5 endo-mannanases shows that dramatic differences in the length of three loops modify the active center accessibility and thus modulate the specificity from endo to exo. The most striking and significant difference is the extended loop between strand beta8 and helix alpha8 comprising residues 378-412. This insertion forms a "double" steric barrier, formed by two short beta-strands that function to "block" the substrate binding cleft at the edge of the -1 subsite forming the "exo" active center topology of CmMan5A. |
| Databáze: | OpenAIRE |
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