5cel: Difference between revisions

Detailed information has been obtained, by means of protein X-ray, crystallography, on how a cellulose chain is bound in the, cellulose-binding tunnel of cellobiohydrolase I (CBHI), the major, cellulase in the hydrolysis of native, crystalline cellulose by the fungus, Trichoderma reesei. Three high-resolution crystal structures of different, catalytically deficient mutants of CBHI in complex with cellotetraose, cellopentaose and cellohexaose have been refined at 1.9, 1.7 and 1.9 A, resolution, respectively. The observed binding of cellooligomers in the, tunnel allowed unambiguous identification of ten well-defined subsites for, glucosyl units that span a length of approximately 50 A. All bound, oligomers have the same directionality and orientation, and the positions, of the glucosyl units in each binding site agree remarkably well between, the different complexes. The binding mode observed here corresponds to, that expected during productive binding of a cellulose chain. The, structures support the hypothesis that hydrolysis by CBHI proceeds from, the reducing towards the non-reducing end of a cellulose chain, and they, provide a structural explanation for the observed distribution of initial, hydrolysis products.

5CEL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hypocrea_jecorina Hypocrea jecorina] with NAG and CO as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cellulose_1,4-beta-cellobiosidase Cellulose 1,4-beta-cellobiosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.91 3.2.1.91] Structure known Active Sites: CAT and COB. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=5CEL OCA].  

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