Control of initiation of pMB1 replication: purified Rop protein and RNA I affect primer formation in vitro.
We show that a protein of 63 amino acids is the product of the rop gene, a gene which negatively regulates the copy number of plasmids of the ColE1 family. Rop protein purified to homogeneity inhibits ColE1 plasmid replication in a bacterial extract. Furthermore, we show that Rop inhibition requires RNA I. In a purified in vitro system that can support primer transcription and processing, Rop affects primer formation in two ways: first, it elicits transcription termination oat nucleotide 220, and second, it increases the ability of RNA I to inhibit RNAase H processing of the primer. The analysis of these data and the comparison with the results obtained in vivo with transcription fusion experiments allow us to propose a tentative model of the molecular mechanism underlying Rop-RNA I inhibition.
D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics*; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D005809:Genes, Regulator; D010957:Plasmids; D012313:RNA / Q000494:pharmacology*; D012329:RNA, Bacterial / Q000235:genetics; D014158:Transcription, Genetic
D004269:DNA, Bacterial; C042027:RNA I; D012329:RNA, Bacterial; D012313:RNA