1v2x

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models 1v2x, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

TrmH

Overview

The tRNA(Gm18) methyltransferase (TrmH) catalyzes the 2'-O methylation of, guanosine 18 (Gua18) of tRNA. We solved the crystal structure of Thermus, thermophilus TrmH complexed with S-adenosyl-L-methionine at 1.85 A, resolution. The catalytic domain contains a deep trefoil knot, which, mutational analyses revealed to be crucial for the formation of the, catalytic site and the cofactor binding pocket. The tRNA, dihydrouridine(D)-arm can be docked onto the dimeric TrmH, so that the, tRNA D-stem is clamped by the N- and C-terminal helices from one subunit, while the Gua18 is modified by the other subunit. Arg41 from the other, subunit enters the catalytic site and forms a hydrogen bond with a bound, sulfate ion, an RNA main chain phosphate analog, thus activating its, nucleophilic state. Based on Gua18 modeling onto the active site, we, propose that once Gua18 binds, the phosphate group activates Arg41, which, then deprotonates the 2'-OH group for methylation.

About this Structure

1V2X is a Single protein structure of sequence from Thermus thermophilus with PO4 and SAM as ligands. Active as tRNA guanosine-2'-O-methyltransferase, with EC number 2.1.1.34 Full crystallographic information is available from OCA.

Reference

Deep knot structure for construction of active site and cofactor binding site of tRNA modification enzyme., Nureki O, Watanabe K, Fukai S, Ishii R, Endo Y, Hori H, Yokoyama S, Structure. 2004 Apr;12(4):593-602. PMID:15062082

Page seeded by OCA on Sun Nov 25 04:32:56 2007