2PKC: CRYSTAL STRUCTURE OF CALCIUM-FREE PROTEINASE K AT 1.5 ANGSTROMS RESOLUTION

Citation:
Abstract
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proteinase K at 1.5-A resolution show that there are no cuts in the polypeptide backbone (i.e. no autolysis), Ca 1 has been replaced by Na+, while Ca 2 has been substituted by a water associated with a larger but locally confined structural change at that site.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.
PDB ID: 2PKCDownload
MMDB ID: 58154
PDB Deposition Date: 1993/6/4
Updated in MMDB: 2017/12
Experimental Method:
x-ray diffraction
Resolution: 1.5  Å
Source Organism:
Similar Structures:
Biological Unit for 2PKC: monomeric; determined by author
Molecular Components in 2PKC
Label Count Molecule
Protein (1 molecule)
1
Proteinase K
Molecule annotation
Chemical (1 molecule)
1
1
* Click molecule labels to explore molecular sequence information.

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