3cel
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ACTIVE-SITE MUTANT E212Q DETERMINED AT PH 6.0 WITH CELLOBIOSE BOUND IN THE ACTIVE SITE
OverviewOverview
The roles of the residues in the catalytic trio Glu212-Asp214-Glu217 in, cellobiohydrolase I (CBHI) from Trichoderma reesei have been investigated, by changing these residues to their isosteric amide counterparts. Three, mutants, E212Q, D214N and E217Q, were constructed and expressed in T., reesei. All three point mutations significantly impair the catalytic, activity of the enzyme, although all retain some residual activity. On the, small chromophoric substrate CNP-Lac, the kcat values were reduced to, 1/2000, 1/85 and 1/370 of the wild-type activity, respectively, whereas, the KM values remained essentially unchanged. On insoluble crystalline, cellulose, BMCC, no significant activity was detected for the E212Q and, E217Q mutants, whereas the D214N mutant retained residual activity. The, ... [(full description)]
About this StructureAbout this Structure
3CEL is a [Single protein] structure of sequence from [Trichoderma reesei] with NAG and CD as [ligands]. Active as [[1]], with EC number [3.2.1.91]. Full crystallographic information is available from [OCA].
ReferenceReference
Activity studies and crystal structures of catalytically deficient mutants of cellobiohydrolase I from Trichoderma reesei., Stahlberg J, Divne C, Koivula A, Piens K, Claeyssens M, Teeri TT, Jones TA, J Mol Biol. 1996 Nov 29;264(2):337-49. PMID:8951380
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