| Structural highlights
Function
TRMH_THET8 Catalyzes the 2'-O methylation of guanosine at position 18 in tRNA. Type I methylase, which methylates all tRNAs.[1] [2] [3] [4]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
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.
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[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hori H, Suzuki T, Sugawara K, Inoue Y, Shibata T, Kuramitsu S, Yokoyama S, Oshima T, Watanabe K. Identification and characterization of tRNA (Gm18) methyltransferase from Thermus thermophilus HB8: domain structure and conserved amino acid sequence motifs. Genes Cells. 2002 Mar;7(3):259-72. PMID:11918670 doi:10.1046/j.1365-2443.2002.00520.x
- ↑ Nureki O, Watanabe K, Fukai S, Ishii R, Endo Y, Hori H, Yokoyama S. Deep knot structure for construction of active site and cofactor binding site of tRNA modification enzyme. Structure. 2004 Apr;12(4):593-602. PMID:15062082 doi:10.1016/j.str.2004.03.003
- ↑ Ochi A, Makabe K, Kuwajima K, Hori H. Flexible recognition of the tRNA G18 methylation target site by TrmH methyltransferase through first binding and induced fit processes. J Biol Chem. 2010 Mar 19;285(12):9018-29. PMID:20053984 doi:10.1074/jbc.M109.065698
- ↑ Ochi A, Makabe K, Yamagami R, Hirata A, Sakaguchi R, Hou YM, Watanabe K, Nureki O, Kuwajima K, Hori H. The catalytic domain of topological knot tRNA methyltransferase (TrmH) discriminates between substrate tRNA and nonsubstrate tRNA via an induced-fit process. J Biol Chem. 2013 Aug 30;288(35):25562-25574. PMID:23867454 doi:10.1074/jbc.M113.485128
- ↑ Nureki O, Watanabe K, Fukai S, Ishii R, Endo Y, Hori H, Yokoyama S. Deep knot structure for construction of active site and cofactor binding site of tRNA modification enzyme. Structure. 2004 Apr;12(4):593-602. PMID:15062082 doi:10.1016/j.str.2004.03.003
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