title: Sequence, localization and characteristics of the replicator region of the symbiotic plasmid of Rhizobium etli.
abstract: The replicator region of the symbiotic plasmid of Rhizobium etli CFN42 was cloned and sequenced. A plasmid derivative (pH3) harbouring a 5-6 kb HindIII fragment from the symbiotic plasmid was found to be capable of independent replication and eliminated the symbiotic plasmid when introduced into a R. etli CFNX101 strain (a recA derivative). The stability and the copy number of pH3 were the same as that of the symbiotic plasmid, indicating that the information required for stable replication and incompatibility resides in the 5.6 kb HindIII fragment. The sequence analysis of this fragment showed the presence of three ORFs similar in sequence analysis of this fragment showed the presence of three ORFs similar in sequence and organization to repA, repB and repC described for the replicator regions of the Agrobacterium plasmids pTiB653 and pRiA4b and for the R. leguminosarum cryptic plasmid pRL8JI. Hybridization studies showed that p42d-like replicator sequences are found in the symbiotic plasmids of other R. etli strains and in a 'cryptic' plasmid of R. tropici.
authors.affiliation: Departamento de Genética Molecular, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Ramírez-Romero
authors.affiliation: Departamento de Genética Molecular, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bustos
authors.affiliation: Departamento de Genética Molecular, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Girard
authors.affiliation: Departamento de Genética Molecular, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Oscar
authors.initials: O
authors.lastname: Rodríguez
authors.affiliation: Departamento de Ecología Molecular, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cevallos
authors.affiliation: Departamento de Genética Molecular, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Dávila
mesh_terms: D003001:Cloning, Molecular; D004261:DNA Replication; D018628:Gene Dosage; D018014:Gene Transfer Techniques; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D015183:Restriction Mapping; D012231:Rhizobium / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013559:Symbiosis / Q000235:genetics*