The large nonsymbiotic plasmid pRmeGR4a of Rhizobium meliloti GR4 encodes a protein involved in replication that has homology with RepC proteins of Agrobacterium plasmids

Abstract

The large plasmid, pRmeGR4a, of Rhizobium meliloti GR4 is a nonsymbiotic, self-transmissible replicon that shows a high degree of stability. Plasmid replication and stabilization functions are located on a 4.8-kb PstI fragment. Analysis of the nucleotide sequence of this DNA region revealed the presence of six open reading frames (ORFs) with coding capabilities; all are transcribed in the same direction. Only one of the ORFs (ORF3) seems to be essential for replication. Its predicted protein sequence shows homology with RepC, a protein that has been suggested to be involved in the replication of Agrobacterium Ri and Ti plasmids.