2pkc
CRYSTAL STRUCTURE OF CALCIUM-FREE PROTEINASE K AT 1.5 ANGSTROMS RESOLUTION
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OverviewOverview
Proteinase K from the fungus Tritirachium album Limber binds two Ca2+ ions, one strongly (Ca 1) and the other weakly (Ca 2). Removal of these cations reduces the stability of proteinase K as shown by thermal denaturation, but the proteolytic activity is unchanged. The x-ray structures of native and Ca(2+)-free proteinase K at 1.5-A resolution show that there are no cuts in the polypeptide backbone (i.e. no autolysis), Ca 1 has been replaced by Na+, while Ca 2 has been substituted by a water associated with a larger but locally confined structural change at that site. A small but concerted geometrical shift is transmitted from the Ca 1 site via eight secondary structure elements to the substrate recognition site (Gly100-Tyr104, and Ser132-Gly136) but not to the catalytic triad (Asp39,His69,Ser224). This is accompanied by positional changes of localized waters.
About this StructureAbout this Structure
2PKC is a Single protein structure of sequence from Engyodontium album with as ligand. Active as Peptidase K, with EC number 3.4.21.64 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of calcium-free proteinase K at 1.5-A resolution., Muller A, Hinrichs W, Wolf WM, Saenger W, J Biol Chem. 1994 Sep 16;269(37):23108-11. PMID:8083213
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