Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, 97239, USA.
Future Microbiol. 2010 Sep;5(9):1403-12. doi: 10.2217/fmb.10.90.
Studying the organization and conservation of the TonB systems across the genus Vibrio, we can tease out trends in gene arrangement and function that lead to clues about the evolution and necessity of the proteins in multiple TonB systems. The TonB2 systems, with additional TtpC proteins, are in general more promiscuous regarding their interactions with many different TonB-dependent transporters in the outer membrane. Studies show that the TtpC protein spans the periplasmic space, suggesting that it can be the connection between the energy from the proton motive force and the outer membrane protein receptors, which the shorter TonB2 cannot provide. As an earlier system, the combination of the TtpC protein and a TonB2 system must have been necessary for the function of the smaller TonB2 protein and to transduce energy in a medium that can have osmotic challenges.
研究弧菌属中 TonB 系统的组织和保护，我们可以梳理出基因排列和功能的趋势，这些趋势为多个 TonB 系统中蛋白质的进化和必要性提供线索。TonB2 系统，加上额外的 TtpC 蛋白，通常在与外膜中许多不同的依赖 TonB 的转运蛋白的相互作用方面更加混杂。研究表明，TtpC 蛋白跨越周质空间，表明它可以是质子动力势和外膜蛋白受体之间能量的连接，而较短的 TonB2 则无法提供。作为一个早期的系统，TtpC 蛋白和 TonB2 系统的组合对于较小的 TonB2 蛋白的功能和在可能具有渗透挑战的介质中传递能量是必要的。
