5A95
Crystal structure of beta-glucanase SdGluc5_26A from Saccharophagus degradans in complex with tetrasaccharide A, form 2
Summary for 5A95
Entry DOI | 10.2210/pdb5a95/pdb |
Related | 5A8M 5A8N 5A8O 5A8P 5A8Q 5A94 |
Descriptor | PUTATIVE RETAINING B-GLYCOSIDASE, beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose, MAGNESIUM ION, ... (7 entities in total) |
Functional Keywords | hydrolase, cazyme, glycoside hydrolase, saccharophagus degradans, beta-glucanase, gh5_26 |
Biological source | SACCHAROPHAGUS DEGRADANS 2-40 |
Total number of polymer chains | 3 |
Total formula weight | 128492.45 |
Authors | Sulzenbacher, G.,Lafond, M.,Freyd, T.,Henrissat, B.,Coutinho, R.M.,Berrin, J.G.,Garron, M.L. (deposition date: 2015-07-17, release date: 2016-01-20, Last modification date: 2024-01-10) |
Primary citation | Lafond, M.,Sulzenbacher, G.,Freyd, T.,Henrissat, B.,Berrin, J.G.,Garron, M.L. The Quaternary Structure of a Glycoside Hydrolase Dictates Specificity Towards Beta-Glucans J.Biol.Chem., 291:7183-, 2016 Cited by PubMed Abstract: In the Carbohydrate-Active Enzyme (CAZy) database, glycoside hydrolase family 5 (GH5) is a large family with more than 6,000 sequences. Among the 51 described GH5 subfamilies, subfamily GH5_26 contains members that display either endo-β(1,4)-glucanase or β(1,3;1,4)-glucanase activities. In this study, we focused on the GH5_26 enzyme fromSaccharophagus degradans(SdGluc5_26A), a marine bacterium known for its capacity to degrade a wide diversity of complex polysaccharides.SdGluc5_26A displays lichenase activity toward β(1,3;1,4)-glucans with a side cellobiohydrolase activity toward β(1,4)-glucans. The three-dimensional structure ofSdGluc5_26A adopts a stable trimeric quaternary structure also observable in solution. The N-terminal region ofSdGluc5_26A protrudes into the active site of an adjacent monomer. To understand whether this occupation of the active site could influence its activity, we conducted a comprehensive enzymatic characterization ofSdGluc5_26A and of a mutant truncated at the N terminus. Ligand complex structures and kinetic analyses reveal that the N terminus governs the substrate specificity ofSdGluc5_26A. Its deletion opens the enzyme cleft at the -3 subsite and turns the enzyme into an endo-β(1,4)-glucanase. This study demonstrates that experimental approaches can reveal structure-function relationships out of reach of current bioinformatic predictions. PubMed: 26755730DOI: 10.1074/JBC.M115.695999 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (1.35 Å) |
Structure validation
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