2yok
From Proteopedia
Cellobiohydrolase I Cel7A from Trichoderma harzianum at 1.7 A resolution
Structural highlights
FunctionGUX1_TRIHA The biological conversion of cellulose to glucose generally requires three types of hydrolytic enzymes: (1) Endoglucanases which cut internal beta-1,4-glucosidic bonds; (2) Exocellobiohydrolases that cut the dissaccharide cellobiose from the non-reducing end of the cellulose polymer chain; (3) Beta-1,4-glucosidases which hydrolyze the cellobiose and other short cello-oligosaccharides to glucose. Publication Abstract from PubMedAiming to contribute towards the characterization of new, biotechnologically relevant cellulolytic enzymes, we report here the first crystal structure of the catalytic core domain of Cel7A (CBHI) from the filamentous fungus Trichoderma harzianum IOC 3844. Our structural studies and molecular dynamics simulations show that the flexibility of Tyr260, in comparison to the Tyr247 from the homologous T. reesei Cel7A, is enhanced due to the short side chains of adjacent Val216 and Ala384 residues and creates an additional gap at the side face of the catalytic tunnel. T. harzianum CBHI also has a shortened loop at the entrance of the cellulose-binding tunnel, which has been described to interact with the substrate in T. reesei Cel7A. These structural features might explain why T. harzianum enzyme displays higher k(cat) and K(m) values and lower product inhibition on both glucosides and lactosides substrates as compared to T. reesei Cel7A. (c) 2012 The Authors Journal compilation (c) 2012 FEBS. Joint x-ray crystallographic and molecular dynamics study of cellobiohydrolase i from trichoderma harzianum: deciphering the structural features of cellobiohydrolase catalytic activity.,Textor LC, Colussi F, Silveira RL, Serpa V, de Mello BL, Muniz JR, Squina FM, Pereira N Jr, Skaf MS, Polikarpov I FEBS J. 2012 Oct 31. doi: 10.1111/febs.12049. PMID:23114223[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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