Kirsebom L A, Amons R, Isaksson L A
Eur J Biochem. 1986 May 2;156(3):669-75. doi: 10.1111/j.1432-1033.1986.tb09630.x.
The amino acid sequences of mutationally altered ribosomal protein L7/L12 from four different rplL mutants of Escherichia coli were determined and correlated with some features of the mutant ribosomes. Two of the rplL mutations are deletions around position 40, which give rise to a shortened hinge region between the two domains of L7/L12. The other two mutants harbor point mutations at position 74 (Gly----Asp) or at position 82 (Glu----Lys), which are in or close to an evolutionarily conserved sequence in the C-terminal domain. The two latter mutations are associated with decreased rates of growth and translational elongation. All four mutants show increased nonsense codon read-through in vivo. Ribosomes from one of the deletion mutants show clearly increased missense error rates in vitro.
测定了来自大肠杆菌四个不同rplL突变体的经突变改变的核糖体蛋白L7/L12的氨基酸序列，并将其与突变核糖体的一些特征相关联。其中两个rplL突变是40位左右的缺失，这导致L7/L12两个结构域之间的铰链区缩短。另外两个突变体在74位（甘氨酸→天冬氨酸）或82位（谷氨酸→赖氨酸）存在点突变，这些位置位于C端结构域中一个进化保守序列内或附近。后两个突变与生长速率和翻译延伸速率降低有关。所有四个突变体在体内均表现出无义密码子通读增加。其中一个缺失突变体的核糖体在体外显示出明显增加的错义错误率。
