Structure of the periplasmic domain of Pseudomonas aeruginosa TolA: evidence for an evolutionary relationship with the TonB transporter protein.

ABSTRACT: The crystal structure of the C-terminal domain III of Pseudomonas aeruginosa TolA has been determined at 1.9 A resolution. The fold is similar to that of the corresponding domain of Escherichia coli TolA, despite the limited amino acid sequence identity of the two proteins (20%). A pattern was discerned that conserves the fold of domain III within the wider TolA family and, moreover, reveals a relationship between TolA domain III and the C-terminal domain of the TonB transporter proteins. We propose that the TolA and TonB C-terminal domains have a common evolutionary origin and are related by means of domain swapping, with interesting mechanistic implications. We have also determined the overall shape of the didomain, domains II + III, of P.aeruginosa TolA by solution X-ray scattering. The

SUBMITTER: Witty M 

PROVIDER: S-EPMC126161 | biostudies-literature | 2002 Aug

REPOSITORIES: biostudies-literature