Function and evolution of plasmid-borne genes for pyrimidine biosynthesis in Borrelia spp.

ABSTRACT: The thyX gene for thymidylate synthase of the Lyme borreliosis (LB) agent Borrelia burgdorferi is located in a 54-kb linear plasmid. In the present study, we identified an orthologous thymidylate synthase gene in the relapsing fever (RF) agent Borrelia hermsii, located it in a 180-kb linear plasmid, and demonstrated its expression. The functions of the B. hermsii and B. burgdorferi thyX gene products were evaluated both in vivo, by complementation of a thymidylate synthase-deficient Escherichia coli mutant, and in vitro, by testing their activities after purification. The B. hermsii thyX gene complemented the thyA mutation in E. coli, and purified B. hermsii ThyX protein catalyzed the conversion of dTMP from dUMP. In contrast, the B. burgdorferi ThyX protein had only weakly detectable acti

SUBMITTER: Zhong J 

PROVIDER: S-EPMC1347342 | biostudies-literature | 2006 Feb

REPOSITORIES: biostudies-literature