Moureau P, Di Giambattista M, Cocito C
Biochim Biophys Acta. 1983 Mar 10;739(2):164-72. doi: 10.1016/0167-4781(83)90026-x.
Transient incubation of bacterial ribosomes with virginiamycin M produces a lasting damage of 50 S ribosomal subunits, whereby the elongation of peptide chains is still blocked after removal of the antibiotic. To elucidate the mechanism of this inactivation, ribosomal proteins were stepwise removed from 50 S subunits previously incubated with virginiamycin M, and cores were submitted to three functional tests. Total removal of proteins L7, L8, L12 and L16, and partial removal of L6, L9, L10 and L11, resulted in a loss of the virginiamycin M-induced alteration. When the split protein fractions were added back to these cores, unaltered functional particles were obtained. The reconstituted subunits, on the other hand, proved fully sensitive to virginiamycin M in vitro as they underwent, upon transient contact with the antibiotic, an alteration comparable to that of native particles. It is concluded that the virginiamycin M-induced ribosome damage is due to the production of a stable conformational change of the 50 S subunit. These data parallel those of an accompanying paper (Cocito, C., Vanlinden, F. and Branlant, C. (1983) Biochim. Biophys. Acta 739, 158-163) showing the intactness of all rRNA species from ribosomes treated in vivo and in vitro with virginiamycin M.
用维吉尼亚霉素M短暂孵育细菌核糖体，会对50 S核糖体亚基造成持久性损伤，即便是在去除抗生素后，肽链的延伸仍会受阻。为阐明这种失活机制，从先前用维吉尼亚霉素M孵育过的50 S亚基中逐步去除核糖体蛋白，并对核糖体核心进行三项功能测试。完全去除蛋白L7、L8、L12和L16，以及部分去除L6、L9、L10和L11，会导致维吉尼亚霉素M诱导的改变消失。当将分离的蛋白组分重新添加到这些核心中时，可获得功能未改变的颗粒。另一方面，重构的亚基在体外对维吉尼亚霉素M完全敏感，因为它们在与抗生素短暂接触后，会发生与天然颗粒类似的改变。结论是，维吉尼亚霉素M诱导的核糖体损伤是由于50 S亚基产生了稳定的构象变化。这些数据与同期发表的一篇论文（Cocito, C., Vanlinden, F. 和 Branlant, C. (1983) Biochim. Biophys. Acta 739, 158 - 163）的数据一致，该论文表明在用维吉尼亚霉素M进行体内和体外处理的核糖体中，所有rRNA种类均保持完整。
