3hfy
Mutant of tRNA-guanine transglycosylase (K52M)
Structural highlights
FunctionTGT_ZYMMO Exchanges the guanine residue with 7-aminomethyl-7-deazaguanine in tRNAs with GU(N) anticodons (tRNA-Asp, -Asn, -His and -Tyr). After this exchange, a cyclopentendiol moiety is attached to the 7-aminomethyl group of 7-deazaguanine, resulting in the hypermodified nucleoside queuosine (Q) (7-(((4,5-cis-dihydroxy-2-cyclopenten-1-yl)amino)methyl)-7-deazaguanosine).[HAMAP-Rule:MF_00168] 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 PubMedThe tRNA-modifying enzyme tRNA-guanine transglycosylase (Tgt) is a putative target for new selective antibiotics against Shigella bacteria. The formation of a Tgt homodimer was suggested on the basis of several crystal structures of Tgt in complex with RNA. In the present study, noncovalent mass spectrometry was used (i) to confirm the dimeric oligomerization state of Tgt in solution and (ii) to evidence the binding stoichiometry of the complex formed between Tgt and its full-length substrate tRNA. To further investigate the importance of Tgt protein-protein interaction, point mutations were introduced into the dimer interface in order to study their influence on the formation of the catalytically active complex. Enzyme kinetics revealed a reduced catalytic activity of these mutated variants, which could be related to a destabilization of the dimer formation as evidenced by both noncovalent mass spectrometry and X-ray crystallography. Finally, the effect of inhibitor binding was investigated by noncovalent mass spectrometry, thus providing the binding stoichiometries of Tgt:inhibitor complexes and showing competitive interactions in the presence of tRNA. Inhibitors that display an influence on the formation of the dimer interface in the crystal structure are promising candidates to alter the protein-protein interaction, which could provide a new way to inhibit Tgt. An integrative approach combining noncovalent mass spectrometry, enzyme kinetics and X-ray crystallography to decipher Tgt protein-protein and protein-RNA interaction.,Ritschel T, Atmanene C, Reuter K, Van Dorsselaer A, Sanglier-Cianferani S, Klebe G J Mol Biol. 2009 Nov 6;393(4):833-47. Epub 2009 Jul 21. PMID:19627989[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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