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Crystal Structure of Cel5A (EG2) from Hypocrea jecorina (Trichoderma reesei)Crystal Structure of Cel5A (EG2) from Hypocrea jecorina (Trichoderma reesei)
Structural highlights
FunctionGUN2_HYPJE 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 PubMedInterest in generating lignocellulosic biofuels through enzymatic hydrolysis continues to rise as nonrenewable fossil fuels are depleted. The high cost of producing cellulases, hydrolytic enzymes that cleave cellulose into fermentable sugars, currently hinders economically viable biofuel production. Here, we report the crystal structure of a prevalent endoglucanase in the biofuels industry, Cel5A from the filamentous fungus Hypocrea jecorina. The structure reveals a general fold resembling that of the closest homolog with a high-resolution structure, Cel5A from Thermoascus aurantiacus. Consistent with previously described endoglucanase structures, the H. jecorina Cel5A active site contains a primarily hydrophobic substrate binding groove and a series of hydrogen bond networks surrounding two catalytic glutamates. The reported structure, however, demonstrates stark differences between side-chain identity, loop regions, and the number of disulfides. Such structural information may aid efforts to improve the stability of this protein for industrial use while maintaining enzymatic activity through revealing nonessential and immutable regions. A structural study of Hypocrea jecorina Cel5A.,Lee TM, Farrow MF, Arnold FH, Mayo SL Protein Sci. 2011 Nov;20(11):1935-40. doi: 10.1002/pro.730. Epub 2011 Sep, 27. PMID:21898652[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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