Stark M J, Cundliffe E
Eur J Biochem. 1979 Dec;102(1):101-5. doi: 10.1111/j.1432-1033.1979.tb06267.x.
A spontaneously occurring thiostrepton-resistant mutant of Bacillus megaterium has been shown to yield ribosomes lacking protein BM-L11, a protein immunologically related to Escherichia coli ribosomal protein L11. Here we have demonstrated that the mutant strain has acquired the relaxed phenotype and is unable to synthesise guanosine tetraphosphate and pentaphosphate in vivo. Ribosomes from the mutant strain are unable to support the synthesis of these two compounds in vitro, but this deficiency can be overcome by re-addition of purified protein BM-L11 to the ribosomes. Thus protein BM-L11 appears to be indispensable for the synthesis of guanosine tetraphosphate and pentaphosphate; the implications of this observation are discussed.
巨大芽孢杆菌的一种自发产生的硫链丝菌素抗性突变体已被证明会产生缺乏蛋白质BM-L11的核糖体，该蛋白质与大肠杆菌核糖体蛋白L11存在免疫相关性。在此我们证明，该突变菌株获得了松弛型表型，并且在体内无法合成鸟苷四磷酸和鸟苷五磷酸。来自突变菌株的核糖体在体外无法支持这两种化合物的合成，但通过向核糖体重新添加纯化的蛋白质BM-L11可以克服这一缺陷。因此，蛋白质BM-L11似乎对于鸟苷四磷酸和鸟苷五磷酸的合成是不可或缺的；本文讨论了这一观察结果的意义。
