title: Characterization of the fluorescent bimane derivative of E. coli initiator transfer RNA (tRNAfMet).
abstract: The invariant modified base 4-thiouridine of the E. Coli initiator tRNA was chemically modified using a sulfhydryl specific fluorogenic probe, monobromobimane. The modified tRNAfMet is virtually indistinguishable biochemically from the native form in the aminoacylation and formylation reactions, and in its binding behavior to the ribosomal P site. Fluorescence quenching by I- increases 40% when the modified tRNA is charged with formylmethionine, even at this relatively well-shielded position in the tRNA elbow. Most important, the fluorescence polarization increases by a factor of 2, to almost the irrotational value, when fMet-tRNAfMet binds to the ribosomal P site, providing a useful tool for studying fMet-tRNAfMet-ribosome interaction equilibria and kinetics.
mesh_terms: D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D001952:Bridged-Ring Compounds; D004926:Escherichia coli; D007454:Iodides; D007700:Kinetics; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012358:RNA, Transfer, Met; D013050:Spectrometry, Fluorescence; D013891:Thiouridine / Q000378:metabolism
chemical_list: D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D001952:Bridged-Ring Compounds; D007454:Iodides; D012346:RNA, Transfer, Amino Acyl; D012358:RNA, Transfer, Met; C021149:bimanes; C024988:tRNA, formylmethionine-; D013891:Thiouridine