1r5d
From Proteopedia
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X-ray structure of bovine seminal ribonuclease swapping dimer from a new crystal form
Overview
Bovine seminal ribonuclease (BS-RNase) is a unique member of the, pancreatic-like ribonuclease superfamily. This enzyme exists as two, conformational isomers with distinctive biological properties. The, structure of the major isomer is characterized by the swapping of the, N-terminal segment (MxM BS-RNase). In this article, the crystal structures, of the ligand-free MxM BS-RNase and its complex with, 2'-deoxycitidylyl(3',5')-2'-deoxyadenosine derived from isomorphous, crystals have been refined. Interestingly, the comparison between this, novel ligand-free form and the previously published sulfate-bound, structure reveals significant differences. In particular, the ligand-free, MxM BS-RNase is closer to the structure of MxM BS-RNase productive, complexes than to the sulfate-bound form. These results reveal that MxM, BS-RNase presents a remarkable flexibility, despite the structural, constraints of the interchain disulfide bridges and the swapping of the, N-terminal helices. These findings have important implications to the, ligand binding mechanism of MxM BS-RNase. Indeed, a population shift, rather than a substrate-induced conformational transition may occur in the, MxM BS-RNase ligand binding process.
About this Structure
1R5D is a Single protein structure of sequence from Bos taurus. Active as Pancreatic ribonuclease, with EC number 3.1.27.5 Full crystallographic information is available from OCA.
Reference
Population shift vs induced fit: the case of bovine seminal ribonuclease swapping dimer., Merlino A, Vitagliano L, Sica F, Zagari A, Mazzarella L, Biopolymers. 2004 Apr 15;73(6):689-95. PMID:15048772
Page seeded by OCA on Wed Nov 21 01:16:36 2007
