Functional and mutational analysis of conjugative transfer region 2 (Tra2) from the IncHI1 plasmid R27.

ABSTRACT: The transfer 2 region (Tra2) of the conjugative plasmid drR27 (derepressed R27) was analyzed by PSI-BLAST, insertional mutagenesis, genetic complementation, and an H-pilus assay. Tra2 contains 11 mating-pair formation (Mpf) genes that are essential for conjugative transfer, 9 of which are essential for H-pilus production (trhA, -L, -E, -K, -B, -V, -C, -P, and -W). TrhK has similarity to secretin proteins, suggesting a mechanism by which DNA could traverse the outer membrane of donors. The remaining two Mpf genes, trhU and trhN, play an auxiliary role in H-pilus synthesis and are proposed to be involved in DNA transfer and mating-pair stabilization, respectively. Conjugative transfer abilities were restored for each mutant when complemented with the corresponding transfer gene. In addition

SUBMITTER: Lawley TD 

PROVIDER: S-EPMC145343 | biostudies-literature | 2003 Jan

REPOSITORIES: biostudies-literature