Hackett J, Reeves P
Nucleic Acids Res. 1983 Sep 24;11(18):6487-95. doi: 10.1093/nar/11.18.6487.
We present the nucleotide sequence of the tolC gene of Escherichia coli K12, and the amino acid sequence of the TolC protein (an outer membrane protein) as deduced from it. The mature TolC protein comprises 467 amino acid residues, and, as previously reported (1), a signal sequence of 22 amino acid residues is attached to the N-terminus. The C-terminus of the gene is followed by a stem-loop structure (8 base pair stem, 4 base loop) which may be a rho-independent termination signal. The codon usage of the gene is nonrandom; the major isoaccepting species of tRNA are preferentially utilised, or, among synonomous codons recognized by the same tRNA, those codons are used which can interact better with the anticodon (2,3). In contrast to the codon usage for other outer membrane proteins of E. coli (4) the rare arginine codons AGA and AGG are used once and twice respectively.
我们展示了大肠杆菌K12的tolC基因的核苷酸序列，以及由此推导的TolC蛋白（一种外膜蛋白）的氨基酸序列。成熟的TolC蛋白由467个氨基酸残基组成，并且如先前报道（1）所述，在N端连接有一个22个氨基酸残基的信号序列。该基因的C端后面是一个茎环结构（8个碱基对的茎，4个碱基的环），这可能是一个不依赖ρ因子的终止信号。该基因的密码子使用并非随机；优先使用tRNA的主要同功受体种类，或者在由相同tRNA识别的同义密码子中，使用那些能与反密码子更好相互作用的密码子（2,3）。与大肠杆菌其他外膜蛋白的密码子使用情况（4）相反，罕见的精氨酸密码子AGA和AGG分别使用了一次和两次。
