Cloning and identification of conjugative transfer origins in the Rhizobium meliloti genome.

ABSTRACT: A simple approach was used to identify Rhizobium meliloti DNA regions with the ability to convert a nontransmissible vector into a mobilizable plasmid, i.e., to contain origins of conjugative transfer (oriT, mob). RecA-defective R. meliloti merodiploid populations, where each individual contained a hybrid cosmid from an R. meliloti GR4 gene library, were used as donors en masse in conjugation with another R. meliloti recipient strain, selecting transconjugants for vector-encoded antibiotic resistance. Restriction analysis of cosmids isolated from individual transconjugants resulted in the identification of 11 nonoverlapping DNA regions containing potential oriTs. Individual hybrid cosmids were confirmed to be mobilized from the original recA donors at frequencies ranging from 10(-2) to 10(

SUBMITTER: Herrera-Cervera JA 

PROVIDER: S-EPMC107471 | biostudies-literature | 1998 Sep

REPOSITORIES: biostudies-literature