1lyw
From Proteopedia
CATHEPSIN D AT PH 7.5
Overview
The crystal structure of a catalytically inactive form of cathepsin D (CatDhi) has been obtained at pH 7.5. The N-terminal strand relocates by 30 A from its position in the interdomain beta-sheet and inserts into the active site cleft, effectively blocking substrate access. CatDhi has a five-stranded interdomain beta-sheet and resembles Intermediate 3, a hypothetical structure proposed to be transiently formed during proteolytic activation of the proenzyme precursor. Interconversion between active and inactive forms of CatD is reversible and may be regulated by an ionizable switch involving the carboxylate side chains of Glu 5, Glu 180, and Asp 187. Our findings provide a structural basis for the pH-dependent regulation of aspartic proteinase activity and suggest a novel mechanism for pH-dependent modulation of substrate specificity.
About this Structure
1LYW is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Conformational switching in an aspartic proteinase., Lee AY, Gulnik SV, Erickson JW, Nat Struct Biol. 1998 Oct;5(10):866-71. PMID:9783744 Page seeded by OCA on Sat May 3 00:26:05 2008
