Structure and function of DnaA N-terminal domains: Specific sites and mechanisms in inter-DnaA interaction and in DnaB helicase loading on oriC

Yoshito Abe, Takaaki Jo, Yusaku Matsuda, Chika Matsunaga, Tsutomu Katayama, Tadashi Ueda

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76 Citations (Scopus)

Abstract

DnaA forms a homomultimeric complex with the origin of chromosomal replication (oriC) to unwind duplex DNA. The interaction of the DnaA N terminus with the DnaB helicase is crucial for the loading of DnaB onto the unwound region. Here, we determined the DnaA N terminus structure using NMR. This region (residues 1-108) consists of a rigid region (domain I) and a flexible region (domain II). Domain I has an α-α-β-β-α-β motif, similar to that of the K homology (KH) domain, and has weak affinity for oriC single-stranded DNA, consistent with KH domain function. A hydrophobic surface carrying Trp-6 most likely forms the interface for domain I dimerization. Glu-21 is located on the opposite surface of domain I from the Trp-6 site and is crucial for DnaB helicase loading. These findings suggest a model for DnaA homomultimer formation and DnaB helicase loading on oriC.

Original languageEnglish
Pages (from-to)17816-17827
Number of pages12
JournalJournal of Biological Chemistry
Volume282
Issue number24
DOIs
Publication statusPublished - Jun 15 2007

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All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Medicine(all)
  • Molecular Biology
  • Cell Biology

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