論文

査読有り
2012年10月

Differentiation of the DnaA-oriC Subcomplex for DNA Unwinding in a Replication Initiation Complex

JOURNAL OF BIOLOGICAL CHEMISTRY
  • Shogo Ozaki
  • ,
  • Yasunori Noguchi
  • ,
  • Yasuhisa Hayashi
  • ,
  • Erika Miyazaki
  • ,
  • Tsutomu Katayama

287
44
開始ページ
37458
終了ページ
37471
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1074/jbc.M112.372052
出版者・発行元
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

In Escherichia coli, ATP-DnaA multimers formed on the replication origin oriC promote duplex unwinding, which leads to helicase loading. Based on a detailed functional analysis of the oriC sequence motifs, we previously proposed that the left half of oriC forms an ATP-DnaA subcomplex competent for oriC unwinding, whereas the right half of oriC forms a distinct ATP-DnaA subcomplex that facilitates helicase loading. However, the molecular basis for the functional difference between these ATP-DnaA subcomplexes remains unclear. By analyzing a series of novel DnaA mutants, we found that structurally distinct DnaA multimers form on each half of oriC. DnaA AAA + domain residues Arg-227 and Leu-290 are specifically required for oriC unwinding. Notably, these residues are required for the ATP-DnaA-specific structure of DnaA multimers in complex with the left half of oriC but not for that with the right half. These results support the idea that the ATP-DnaA multimers formed on oriC are not uniform and that they can adopt different conformations. Based on a structural model, we propose that Arg-227 and Leu-290 play a crucial role in inter-ATP-DnaA interaction and are a prerequisite for the formation of unwinding-competent DnaA subcomplexes on the left half of oriC. These residues are not required for the interaction with DnaB, nucleotide binding, or regulatory DnaA-ATP hydrolysis, which further supports their important role in inter-DnaA interaction. The corresponding residues are evolutionarily conserved and are required for unwinding in the initial complexes of Thermotoga maritima, an ancient hyperthermophile. Therefore, our findings suggest a novel and common mechanism for ATP-DnaA-dependent activation of initial complexes.

リンク情報
DOI
https://doi.org/10.1074/jbc.M112.372052
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/22942281
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000310588500075&DestApp=WOS_CPL
ID情報
  • DOI : 10.1074/jbc.M112.372052
  • ISSN : 0021-9258
  • PubMed ID : 22942281
  • Web of Science ID : WOS:000310588500075

エクスポート
BibTeX RIS