1bk1
From Proteopedia
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ENDO-1,4-BETA-XYLANASE C
Overview
Xylanase C from Aspergillus kawachii has an optimum pH of 2.0 and is, stable at pH 1.0. The crystal structure of xylanase C was determined at, 2.0 A resolution (R-factor = 19.4%). The overall structure was similar to, those of other family 11 xylanases. Asp37 and an acid-base catalyst, Glu170, are located at a hydrogen-bonding distance (2.8 A), as in other, xylanases with low pH optima. Asp37 of xylanase C was replaced with, asparagine and other residues by site-directed mutagenesis. Analyses of, the wild-type and mutant enzymes showed that Asp37 is important for high, enzyme activity at low pH. In the case of the asparagine mutant, the, optimum pH shifted to 5.0 and the maximum specific activity decreased to, about 15% of that of the wild-type enzyme. On structural comparison with, ... [(full description)]
About this Structure
1BK1 is a [Single protein] structure of sequence from [Aspergillus kawachii]. Active as [Endo-1,4-beta-xylanase], with EC number [3.2.1.8]. Structure known Active Site: AS. Full crystallographic information is available from [OCA].
Reference
Crystallographic and mutational analyses of an extremely acidophilic and acid-stable xylanase: biased distribution of acidic residues and importance of Asp37 for catalysis at low pH., Fushinobu S, Ito K, Konno M, Wakagi T, Matsuzawa H, Protein Eng. 1998 Dec;11(12):1121-8. PMID:9930661
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