The initiator protein DnaA, chromosomal origin oriC and their interaction to generate origin recognition complex and pre-replication complex like nucleoprotein structures in Escherichia coli

Introduction The assembly of precisely timed nucleoprotein structures comprising an initiator protein bound to a chromosomal origin of replication ensures that initiation of DNA synthesis at each origin occurs only once per cell cycle. The origin recognition complex (ORC) present at a chromosomal origin in yeast Sachromyces cerevisiae is one of the well studied example of such nucleoprotein structure. Recruitment of other proteins to an ORC generates a pre-replication complex (pre-RC), which subsequently recruits a helicase and unwinds DNA duplex. Studies suggest that spatial and temporal similarities exist in the formation of nucleoprotein complexes for both eukaryote and prokaryote. This review briefly introduces the Escherichia coli initiator protein, DnaA, recent findings on the E. coli chromosomal origin, oriC and concludes with an overview of their interactions to produce the nucleoprotein complexes involved in forming bacterial ORC and pre-RC like structures. Conclusion The structural and functional insights of E. coli initiator protein, DnaA and chromosomal origin, oriC, have advanced our understanding of the complex process of replication The initiator protein DnaA, chromosomal origin oriC and their interaction to generate origin recognition complex and pre-replication complex like nucleoprotein structures in