1mkh
From Proteopedia
C-terminal domain of methionyl-tRNA synthetase from Pyrococcus abyssi
Overview
The minimal polypeptide supporting full methionyl-tRNA synthetase (MetRS) activity is composed of four domains: a catalytic Rossmann fold, a connective peptide, a KMSKS domain, and a C-terminal alpha helix bundle domain. The minimal MetRS behaves as a monomer. In several species, MetRS is a homodimer because of a C-terminal domain appended to the core polypeptide. Upon truncation of this C-terminal domain, subunits dissociate irreversibly. Here, the C-terminal domain of dimeric MetRS from Pyrococcus abyssi was isolated and studied. It displays nonspecific tRNA-binding properties and has a crystalline structure closely resembling that of Trbp111, a dimeric tRNA-binding protein found in many bacteria and archaea. The obtained 3D model was used to direct mutations against dimerization of Escherichia coli MetRS. Comparison of the resulting mutants to native and C-truncated MetRS shows that the presence of the appended C-domain improves tRNA(Met) binding affinity. However, dimer formation is required to evidence the gain in affinity.
About this Structure
1MKH is a Single protein structure of sequence from Pyrococcus abyssi. Full crystallographic information is available from OCA.
Reference
Structure and function of the C-terminal domain of methionyl-tRNA synthetase., Crepin T, Schmitt E, Blanquet S, Mechulam Y, Biochemistry. 2002 Oct 29;41(43):13003-11. PMID:12390027 Page seeded by OCA on Sat May 3 01:17:52 2008
