Koyama Y, Furukawa K
Fermentation Research Institute, AIST, MITI, Ibaraki, Japan.
J Bacteriol. 1990 Jun;172(6):3490-5. doi: 10.1128/jb.172.6.3490-3495.1990.
Tryptophan synthetase genes (trpBA) of the extreme thermophile Thermus thermophilus HB27 were cloned by a novel method of direct plasmid transfer from replica-plated Escherichia coli recombinant colonies to competent T. thermophilus HB27 trpB cells. The nucleotide sequences of the trpBA genes were determined. The amino acid sequences deduced from the nucleotide sequences of Thermus trpB and trpA were found to have identities of 54.8 and 28.7%, respectively, with those of E. coli trpB and trpA genes. Low cysteine content (one in trpB; zero in trpA) is a striking feature of these proteins, which may contribute to their thermostability.
嗜热栖热菌HB27的色氨酸合成酶基因(trpBA)是通过一种新方法克隆得到的,该方法是将复制品平板上的大肠杆菌重组菌落中的质粒直接转移到感受态嗜热栖热菌HB27 trpB细胞中。测定了trpBA基因的核苷酸序列。发现从嗜热栖热菌trpB和trpA的核苷酸序列推导的氨基酸序列与大肠杆菌trpB和trpA基因的氨基酸序列分别具有54.8%和28.7%的同一性。这些蛋白质的一个显著特征是半胱氨酸含量低(trpB中有一个;trpA中为零),这可能有助于它们的热稳定性。