2pkc: Difference between revisions

[[Image:2pkc.jpg|left|200px]]<br /><applet load="2pkc" size="350" color="white" frame="true" align="right" spinBox="true"  

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proteinase K at 1.5-A resolution show that there are no cuts in the polypeptide backbone (i.e. no autolysis), Ca 1 has been replaced by Na+, while Ca 2 has been substituted by a water associated with a larger but locally confined structural change at that site.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.

2PKC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Engyodontium_album Engyodontium album] with <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Peptidase_K Peptidase K], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.64 3.4.21.64] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PKC OCA].  

[[Category: Wolf, W M.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:30:30 2008''