Shao Z, Lin R T, Newman E B
Biology Department, Concordia University, Montreal, Canada.
Eur J Biochem. 1994 Jun 15;222(3):901-7. doi: 10.1111/j.1432-1033.1994.tb18938.x.
We describe here the regulatory and coding region, and DNA sequence, for a newly recognized gene, sdaC, which codes for a hydrophobic protein with several predicted membrane-spanning domains. sdaC and sdaB form a single operon, with 57 bp between the end of sdaC and the start of sdaB. Expression of the sdaCB operon is regulated mainly by catabolite repression, but is also slightly sensitive to regulation by leucine-responsive regulatory protein. Cells carrying sdaC on a multicopy plasmid have increased L-serine transport capacity, insensitive to threonine, suggesting that sdaC might code for a recently described highly specific serine transporter [Kayahara, T., Thelen, P., Ogawa, W., Inaba, K., Tsuda, M., Goldberg, E. B. & Tsuchiya, T. (1992) J. Bacteriol. 174, 7482-7485].
我们在此描述一个新发现的基因sdaC的调控区、编码区及DNA序列，该基因编码一种具有多个预测跨膜结构域的疏水蛋白。sdaC和sdaB形成一个单一操纵子，sdaC末端与sdaB起始处之间间隔57个碱基对。sdaCB操纵子的表达主要受分解代谢物阻遏调控，但对亮氨酸应答调节蛋白的调控也稍有敏感性。携带多拷贝质粒上sdaC的细胞具有增强的L-丝氨酸转运能力，对苏氨酸不敏感，这表明sdaC可能编码一种最近描述的高度特异性丝氨酸转运蛋白[Kayahara, T., Thelen, P., Ogawa, W., Inaba, K., Tsuda, M., Goldberg, E. B. & Tsuchiya, T. (1992) J. Bacteriol. 174, 7482 - 7485]。
