Structural insight into the DNA-binding mode of the primosomal proteins PriA, PriB, and DnaT.

Yen-Hua Huang,Cheng-Yang Huang

doi:10.1155/2014/195162

Abstract

Replication restart primosome is a complex dynamic system that is essential for bacterial survival. This system uses various proteins to reinitiate chromosomal DNA replication to maintain genetic integrity after DNA damage. The replication restart primosome in Escherichia coli is composed of PriA helicase, PriB, PriC, DnaT, DnaC, DnaB helicase, and DnaG primase. The assembly of the protein complexes within the forked DNA responsible for reloading the replicative DnaB helicase anywhere on the chromosome for genome duplication requires the coordination of transient biomolecular interactions. Over the last decade, investigations on the structure and mechanism of these nucleoproteins have provided considerable insight into primosome assembly. In this review, we summarize and discuss our current knowledge and recent advances on the DNA-binding mode of the primosomal proteins PriA, PriB, and DnaT.

Highlights

Genome integrity should be maintained from generation to generation to ensure proper cell function and survival [1,2,3]
To reload DnaB helicase for oriC-independent DNA replication, collapsed DNA replication forks must be reactivated by the replication restart primosome [7, 8]
After DNA repair, the replication restart primosome [11,12,13], a formidable enzymatic machine, can translocate along the single-stranded DNA-binding protein (SSB), unwind the duplex DNA, and prime the Okazaki fragments required for the progression of replication forks [14]

Summary

Introduction

Genome integrity should be maintained from generation to generation to ensure proper cell function and survival [1,2,3]. Genetic analyses suggest that these primosomal proteins are essential replication proteins for bacterial cell growth [12, 16,17,18,19,20,21] These proteins are required for reinitiating chromosomal DNA replication in bacteria; blocking their activities would be detrimental to bacterial survival [22, 23]. Several primosomal proteins, such as PriA, PriB, PriC, and DnaT, are not found in humans; these proteins may be potential targets in developing antibiotics for the six antibiotic-resistant pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.) [24, 25]. We summarize and discuss our current knowledge and recent advances on the DNA-binding mode of the primosomal proteins PriA, PriB, and DnaT

Structural Insights into the DNA-Binding Mode

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Perspectives