16S核糖体RNA在起始因子3核糖体结合中的作用。

The role of 16S rRNA in ribosomal binding of IF-3.

作者信息

Pon C L, Gualerzi C

出版信息

Biochemistry. 1976 Feb 24;15(4):804-11. doi: 10.1021/bi00649a012.

Abstract

The binding of initiation factor IF-3 to Escherichia coli 30S ribosomal subunits has been found to be inhibited by rRNA ligands such as ethidium bromide, polyamines, and monovalent alkali metals. The order of effectiveness of the polyamines (spermine greater than spermidine greater than putrescine) and alkali metals (Li+ greater than Na+ greater than K+) in inhibiting the ribosomal binding of IF-3 parallels their degree of affinity for the RNA. Furthermore, the binding of IF-3 to 30S subunits chemically modified by photooxidation with rose bengal, nitration with tetranitromethane, and reaction with kethoxal, monoperphthalic acid, and p-chloromercuribenzoic acid was studied. Results obtained after the direct treatment of the 30S subunits with the above chemical reagents or upon reconstitution of 30S particles having a modified rRNA or ribosomal proteins indicate that the IF-3 binding site is preferentially lost when the rRNA becomes modified. It was found that IF-3 could bind normally to 30S subunits lacking protein S1 or proteins S11, S12, S19, and S21 (and perhaps S14) which had been cross-linked to IF-3 in other laboratories.

摘要

已发现起始因子IF-3与大肠杆菌30S核糖体亚基的结合受到诸如溴化乙锭、多胺和单价碱金属等rRNA配体的抑制。多胺（精胺＞亚精胺＞腐胺）和碱金属（Li⁺＞Na⁺＞K⁺）在抑制IF-3与核糖体结合方面的有效性顺序与其对RNA的亲和程度相似。此外，还研究了IF-3与经孟加拉玫瑰红光氧化、四硝基甲烷硝化以及与乙二醛、单过邻苯二甲酸和对氯汞苯甲酸反应而化学修饰的30S亚基的结合。用上述化学试剂直接处理30S亚基或在重构具有修饰rRNA或核糖体蛋白的30S颗粒后获得的结果表明，当rRNA被修饰时，IF-3结合位点优先丧失。研究发现，IF-3能够正常结合缺乏蛋白S1或蛋白S11、S12、S19和S21（可能还有S14）的30S亚基，而在其他实验室中这些蛋白已与IF-3交联。