A recurrent general RNA binding domain appended to plant methionyl-tRNA synthetase acts as a cis-acting cofactor for aminoacylation.

ABSTRACT: The cDNA encoding rice methionyl-tRNA synthetase was isolated. The protein exhibited a C-terminal polypeptide appended to a classical MetRS domain. This supplementary domain is related to endothelial monocyte activating polypeptide II (EMAPII), a cytokine produced in mammals after cleavage of p43, a component of the multisynthetase complex. It is also related to Arc1p and Trbp111, two tRNA binding proteins. We expressed rice MetRS and a derivative with a deletion of its EMAPII-like domain. Band-shift analysis showed that this extra-domain provides MetRS with non-specific tRNA binding properties. The EMAPII-like domain contributed a 10-fold decrease in K:(M) for tRNA in the aminoacylation reaction catalyzed by the native enzyme, as compared with the C-terminally truncated MetRS. Consequentl

SUBMITTER: Kaminska M 

PROVIDER: S-EPMC305886 | biostudies-literature | 2000 Dec

REPOSITORIES: biostudies-literature