title: Binding of methylmercuric hydroxide by 4-thiouridine of N-formylmethionyl-tRNA from Escherichia coli.
abstract: The binding of methylmercuric hydroxide to N-formylmethionyl-tRNA of Escherichia coli has been studied. In the absence of magnesium ions, methylmercury binds strongly to 4-thiouridine in the eighth position from the 5' end: the dissociation constant is (1.0 +/- 0.2) X 10(-5) M, and the forward and reverse rate constants for binding are (5.3 +/- 0.5) X 10(4) M-1S-1 and 0.38 +/- 0.02S-1, respectively. The presence of Mg2+ prevents this binding, presumably through some conformational change induced in the structure of N-formylmethionyl-tRNA.
mesh_terms: D001665:Binding Sites; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008433:Mathematics; D008767:Methylmercury Compounds / Q000378:metabolism*; D009239:N-Formylmethionine; D009691:Nucleic Acid Denaturation; D012329:RNA, Bacterial / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D013891:Thiouridine / Q000378:metabolism*
chemical_list: D008767:Methylmercury Compounds; D012329:RNA, Bacterial; D013891:Thiouridine; D009239:N-Formylmethionine; D012343:RNA, Transfer; D008274:Magnesium