title: Isolation of Q nucleoside precursor present in tRNA of an E. coli mutant and its characterization as 7-(cyano)-7-deazaguanosine.
abstract: One of the E. coli mutants selected for deficiency of modified nucleoside Q was found to contain an analogue of Q and normal guanosine in place of Q. The analogue of Q, designated as preQo, was isolated on a large scale from purified tRNATyr containing preQo. The structure of preQo was determined to be 7-(cyano)-7-deazaguanosine by comparison of its ultraviolet absorption spectra, thin-layer chromatographic mobility and mass spectrum with those of synthetic material.
mesh_terms: D004926:Escherichia coli / Q000032:analysis*; D006151:Guanosine / Q000031:analogs & derivatives* / Q000302:isolation & purification; D013058:Mass Spectrometry; D009154:Mutation; D012343:RNA, Transfer / Q000302:isolation & purification; D014443:Tyrosine
chemical_list: D006151:Guanosine; D014443:Tyrosine; D012343:RNA, Transfer