1xzp
From Proteopedia
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Structure of the GTP-binding protein TrmE from Thermotoga maritima
Overview
TrmE is a 50 kDa guanine nucleotide-binding protein conserved between, bacteria and man. It is involved in the modification of uridine bases, (U34) at the first anticodon (wobble) position of tRNAs decoding, two-family box triplets. The precise role of TrmE in the modification, reaction is hitherto unknown. Here, we report the X-ray structure of TrmE, from Thermotoga maritima. The structure reveals a three-domain protein, comprising the N-terminal alpha/beta domain, the central helical domain, and the G domain, responsible for GTP binding and hydrolysis. The, N-terminal domain induces dimerization and is homologous to the, tetrahydrofolate-binding domain of N,N-dimethylglycine oxidase., Biochemical and structural studies show that TrmE indeed binds, formyl-tetrahydrofolate. A cysteine residue, necessary for modification of, U34, is located close to the C1-group donor 5-formyl-tetrahydrofolate, suggesting a direct role of TrmE in the modification analogous to DNA, modification enzymes. We propose a reaction mechanism whereby TrmE, actively participates in the formylation reaction of uridine and regulates, the ensuing hydrogenation reaction of a Schiff's base intermediate.
About this Structure
1XZP is a Protein complex structure of sequences from Thermotoga maritima with SO4 as ligand. Full crystallographic information is available from OCA.
Reference
The structure of the TrmE GTP-binding protein and its implications for tRNA modification., Scrima A, Vetter IR, Armengod ME, Wittinghofer A, EMBO J. 2005 Jan 12;24(1):23-33. Epub 2004 Dec 16. PMID:15616586
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