Lázaro E, Rodriguez-Fonseca C, Porse B, Ureña D, Garrett R A, Ballesta J P
Centro de Biologia Molecular Severo Ochoa, Consejo Superior de Investigaciones Cientificas, Madrid, Spain.
J Mol Biol. 1996 Aug 16;261(2):231-8. doi: 10.1006/jmbi.1996.0455.
Sparsomycin, a broad-spectrum antibiotic, acts at the peptidyl transferase centre of the ribosome, stabilizing peptidyl-tRNA binding at the P-site and weakening ternary complex binding. A sparsomycin-resistant mutant was isolated for the archaeon Halobacterium salinarium and shown to lack a post-transcriptional modification of U2603 (Escherichia coli numbering U2584), which is a universally conserved uridine base located within the peptidyl transferase loop of 23 S rRNA. This mutant also exhibited altered sensitivities to the peptidyl transferase antibiotics anisomycin, chloramphenicol and puromycin. Several lines of evidence indicate that the unmodified uridine base lies within the P-substrate site of the peptidyl transferase centre.
稀疏霉素是一种广谱抗生素，作用于核糖体的肽基转移酶中心，稳定肽基 - tRNA在P位点的结合并减弱三元复合物的结合。从嗜盐嗜盐菌古菌中分离出一株对稀疏霉素耐药的突变体，结果显示该突变体缺乏U2603（大肠杆菌编号为U2584）的转录后修饰，U2603是位于23S rRNA肽基转移酶环内的一个普遍保守的尿苷碱基。该突变体对肽基转移酶抗生素茴香霉素、氯霉素和嘌呤霉素的敏感性也发生了改变。多条证据表明，未修饰的尿苷碱基位于肽基转移酶中心的P底物位点内。
