PcnB is required for the rapid degradation of RNAI, the antisense RNA that controls the copy number of ColE1-related plasmids.
The replication of ColE1-related plasmids is controlled by an unstable antisense RNA, RNAI, which can interfere with the successful processing of the RNAII primer of replication. We show here that a host protein, PcnB, supports replication by promoting the decay of RNAI. In bacterial strains deleted for PcnB a stable, active form of RNAI, RNAI*, which appears to be identical to the product of 5'-end processing by RNAase E, accumulates. This leads to a reduction in plasmid copy number. We show, using a GST-PcnB fusion protein, that PcnB does not interfere with RNAI/RNAII binding in vitro. The fusion protein, like PcnB, has polyadenylating activity and is able to polyadenylate RNAI (and also another antisense RNA, CopA) in vitro.
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Institute of Cell and Molecular Biology, University of Edinburgh, UK.
Söderbom
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Wagner
E G
EG
Binnie
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U
Binns
N
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Masters
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M
D000668:Ampicillin Resistance / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015152:Blotting, Northern; D003087:Colicins / Q000037:antagonists & inhibitors; D017931:DNA Primers; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D007700:Kinetics; D008969:Molecular Sequence Data; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism*; D016372:RNA, Antisense / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D003087:Colicins; D017931:DNA Primers; D029968:Escherichia coli Proteins; D016372:RNA, Antisense; D012329:RNA, Bacterial; D011993:Recombinant Fusion Proteins; C007104:colicin immunity proteins; D011062:Polynucleotide Adenylyltransferase; C063643:pcnB protein, E coli