Types | DnaRegion
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Roles | CDS
Coding
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Sequences | BBa_K535008_sequence (Version 1)
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Description
The widespread replicons of repABC and repC families from -proteobacteria share high similarity in their replication initiator proteins (RepC). repC region belongs to a low copy-number plasmid pRmeGR4a from Sinorizobium meliloti GR4. This region contains only two genes: one encoding the initiator protein RepC (46.8 kDa) and other, an antisense RNA (67 nt).
The constitutively expressed countertranscribed RNA (ctRNA) forms a single stem???loop structure that acts as
an intrinsic rho-independent terminator. Transcriptional activity of ctRNA downregulate repC, both have sigma70-like promoters. Promoter of repC (T1) is relatively far from start site and is influenced by transcription of ctRNA which has promoter in reverse direction.
Compatibility between plasmids is the ability to get two or more classes of plasmids at the same organism. The ctRNA is a strong trans-incompatibility factor and negative regulator of repC expression [1], this has been seen in other families of RepC class [2].
RepC is the minimal region required for stable replication of a member of the repC family, it works in Rhizobials .
Notes
In order to have the same result as in pUX19-XKR5 [1] there are 290 bps upstream from start transcription site of repC. To get some repC downstream sequence there are added 51bp.
Source
Low copy number plasmid pRmeGR4a from Sinorizobium meliloti GR4.