IBB PAS Repository

Deciphering the Regulatory Circuits of RA3 Replication Module - Mechanisms of the Copy Number Control

Markowska-Barkic,, Aleksandra and Lewicka, Ewa and Czeredys, Magdalena and Mitura, Monika and Jagura-Burdzy, Grazyna (2022) Deciphering the Regulatory Circuits of RA3 Replication Module - Mechanisms of the Copy Number Control. International Journal of Molecular Sciences, 23 (17). pp. 9964-9995. ISSN 1422-0067


Official URL: https://www.mdpi.com/journal/ijms


The RA3 plasmid, the archetype of IncU incompatibility group, represents a mosaic- modular genome of 45.9 kb. The replication module encompasses repA and repB (initiator) surrounded by two long repetitive sequences DR1 and DR2 of unknown function. Here, we mapped the origin of replication oriV to the 3′ end of repB and showed that oriV was activated by the transcription coming from orf02revp in the adjacent stability module. Using various in vivo and in vitro methods we demonstrated that the repB expression proceeded either from repBp located in the intergenic repA- repB region or from the upstream strong repAp that was autoregulated by RepA. Additionally, the repBp activity was modulated by the transcription from the overlapping, divergently oriented repXp. Both repXmRNA (antisense for repAmRNA) and its small polypeptide product, RepX, were strong incompatibility determinants. Hence, we showed that the sophisticated RA3 copy number control combined the multivalent regulation of repB expression, RepB titration by DR1, and transcriptional activation of oriV, dependent on the RA3 global regulatory network. Similarly organized replicons have been found in diverse bacterial species confirming the significance of these mechanisms in establishing the IncU plasmids in a broad spectrum of hosts

Item Type:Article
Subjects:Q Science > QR Microbiology
Divisions:Department of Microbial Biochemistry
ID Code:2175
Deposited By: prof Grazyna Jagura-Burdzy
Deposited On:07 Sep 2022 09:29
Last Modified:07 Sep 2022 09:29

Repository Staff Only: item control page