6JR8
Flavobacterium johnsoniae GH31 dextranase, FjDex31A, mutant D412A complexed with isomaltotriose
Summary for 6JR8
| Entry DOI | 10.2210/pdb6jr8/pdb |
| Related | 6JR6 6JR7 |
| Descriptor | Candidate alpha-glycosidase Glycoside hydrolase family 31, alpha-D-glucopyranose-(1-6)-alpha-D-glucopyranose-(1-6)-alpha-D-glucopyranose, ACETATE ION, ... (5 entities in total) |
| Functional Keywords | dextranase, flavobacterium johnsoniae, dextran, isomaltose, gh31, hydrolase |
| Biological source | Flavobacterium johnsoniae (strain ATCC 17061 / DSM 2064 / UW101) (Cytophaga johnsonae) |
| Total number of polymer chains | 4 |
| Total formula weight | 388344.07 |
| Authors | Tonozuka, T. (deposition date: 2019-04-02, release date: 2019-04-24, Last modification date: 2024-11-13) |
| Primary citation | Tsutsumi, K.,Gozu, Y.,Nishikawa, A.,Tonozuka, T. Structural insights into polysaccharide recognition by Flavobacterium johnsoniae dextranase, a member of glycoside hydrolase family 31. Febs J., 287:1195-1207, 2020 Cited by PubMed Abstract: Glycoside hydrolase family (GH) 31 contains a large variety of enzymes, but the major members are enzymes that act on relatively small oligosaccharides such as α-glucosidase. Here, we determined the crystal structure of Flavobacterium johnsoniae dextranase (FjDex31A), an enzyme from F. johnsoniae that hydrolyzes a polysaccharide, dextran. FjDex31A is composed of four domains: an N-terminal domain, a catalytic domain, a proximal C-terminal domain, and a distal C-terminal domain, as observed in typical GH31 enzymes. However, the architecture of active site residues in FjDex31A, other than subsite -1, is markedly different from that of other GH31 enzymes. The FjDex31A structure in complex with isomaltotriose shows that Gly273 and Tyr524, both of which interact with an α-glucose residue at subsite -2, as well as Trp376 and Leu308-cisGln309, are especially unique to FjDex31A. Site-directed mutagenesis of Gly273 and Tyr524 resulted in a decrease in the hydrolysis of polysaccharides dextran and pullulan, as well as that of the disaccharide isomaltose. These results suggest that, regardless of the length of sugar chains of the substrates, binding of FjDex31A to the substrates at subsite -2 is likely to be important for its activity. DATABASE: Structural data are available in the Protein Data Bank under the accession numbers 6JR6, 6JR7, and 6JR8. PubMed: 31552702DOI: 10.1111/febs.15074 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.8 Å) |
Structure validation
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