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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1996 May 28;93(11):5522–5526. doi: 10.1073/pnas.93.11.5522

The replication initiator protein pi of the plasmid R6K specifically interacts with the host-encoded helicase DnaB.

P V Ratnakar 1, B K Mohanty 1, M Lobert 1, D Bastia 1
PMCID: PMC39279  PMID: 8643608

Abstract

The replication initiator protein pi of plasmid R6K is known to interact with the seven iterons of the gamma origin/enhancer and activate distant replication origins alpha and beta (ori alpha and ori beta) by pi-mediated DNA looping. Here we show that pi protein specifically interacts in vitro with the host-encoded helicase DnaB. The site of interaction of pi on DnaB has been localized to a 37-aa-long region located between amino acids 151 and 189 of DnaB. The surface of pi that interacts with DnaB has been mapped to the N-terminal region of the initiator protein between residues 1 and 116. The results suggest that during initiation of replication, the replicative helicase DnaB is first recruited to the gamma enhancer by the pi protein. In a subsequent step, the helicase probably gets delivered from ori gamma to ori alpha and ori beta by pi-mediated DNA looping.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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