1wsd

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spinqualitylabelsall models 1wsd, resolution 1.5Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Alkaline M-protease form I crystal strcuture

Overview

M-protease is a subtilisin-family serine protease produced by an, alkaliphilic Bacillus sp. strain. Optimal enzymatic activity of the, protein occurs at pH 12.3. The crystal structure of M-protease (space, group P2(1)2(1)2(1), a = 62.3, b = 75.5, c = 47.2 A) has been refined to a, crystallographic R-factor of 17.2% at 1.5 A resolution. The alkaline, adaptation mechanism of the enzyme was analyzed. Molecular phylogeny, construction was used to determine the amino acid substitutions that, occurred during the high-alkaline adaptation process. This analysis, revealed a decrease in the number of negatively charged amino acids, (aspartic acid and glutamic acid) and lysine residues and an increase in, arginine and neutral hydrophilic amino acids (histidine, asparagine and, glutamine) residues during the course of adaptation. These substitutions, increased the isoelectric point of M-protease. Some of the acquired, arginine residues form hydrogen bonds or ion pairs to combine both N- and, C-terminal regions of M-protease. The substituted residues are localized, to a hemisphere of the globular protein molecule where positional shifts, of peptide segments, relative to those of the less alkaliphilic subtilisin, Carlsberg, are observed. The biased distribution and interactions caused, by the substituted residues seem to be responsible for stabilization of, the conformation in a high-alkaline condition.

About this Structure

1WSD is a Single protein structure of sequence from Bacillus sp. with CA and SO4 as ligands. Full crystallographic information is available from OCA.

Reference

High-resolution crystal structure of M-protease: phylogeny aided analysis of the high-alkaline adaptation mechanism., Shirai T, Suzuki A, Yamane T, Ashida T, Kobayashi T, Hitomi J, Ito S, Protein Eng. 1997 Jun;10(6):627-34. PMID:9278275

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