1gci
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THE 0.78 ANGSTROMS STRUCTURE OF A SERINE PROTEASE-BACILLUS LENTUS SUBTILISIN
OverviewOverview
Ultrahigh-resolution X-ray diffraction data from cryo-cooled, B. lentus, subtilisin crystals has been collected to a resolution of 0.78 A. The, refined model coordinates have a rms deviation of 0.22 A relative to the, same structure determined at room temperature and 2.0 A resolution., Several regions of main-chain and side-chain disorder have been identified, for 21 out of 269 residues in one polypeptide chain. Hydrogen atoms appear, as significant peaks in the Fo - Fc difference electron density map, and, carbon, nitrogen, and oxygen atoms can be differentiated. The estimated, standard deviation (ESD) for all main-chain non-hydrogen bond lengths is, 0.009 A and 0.5 degrees for bond angles based on an unrestrained, full-matrix least-squares refinement. Hydrogen bonds are resolved in the, serine protease catalytic triad (Ser-His-Asp). Electron density is, observed for an unusual, short hydrogen bond between aspartic acid and, histidine in the catalytic triad. The hydrogen atom, identified by NMR in, numerous serine proteases, appears to be shared by the heteroatoms in the, bond. This represents the first reported correlation between detailed, chemical features identified by NMR and those in a cryo-cooled, crystallographic structure determination at ultrahigh resolution. The, short hydrogen bond, designated "catalytic hydrogen bond", occurs as part, of an elaborate hydrogen bond network, involving Asp of the catalytic, triad. While unusual, these features appear to have conserved analogues in, other serine protease families although specific details differ from, family to family.
About this StructureAbout this Structure
1GCI is a Single protein structure of sequence from Bacillus lentus with SO4, CA and GOL as ligands. Active as Subtilisin, with EC number 3.4.21.62 Full crystallographic information is available from OCA.
ReferenceReference
The 0.78 A structure of a serine protease: Bacillus lentus subtilisin., Kuhn P, Knapp M, Soltis SM, Ganshaw G, Thoene M, Bott R, Biochemistry. 1998 Sep 29;37(39):13446-52. PMID:9753430
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