Role of the amino-terminal region of the DnaA protein in opening of the duplex DNA at the oriC region

Shinji Mima, Yoshihiro Yamagachi, Taemi Kondo, Tomofusa Tsuchiya, Tohru Mizushima

Research output: Contribution to journalArticle

9 Citations (Scopus)


We report in this paper that the amino acid residues Ile-26 and Leu-40 of the DnaA protein are essential for the DNA replication activity in vitro. Lines of evidence to support this conclusion are as follows. Variants of the DnaA protein containing either an Ile-26-Ser or Leu-40-Ser replacement were unable to support oriC DNA replication in vitro. Though the mutant DnaA proteins retained the capability to bind oriC DNA, they were unable to open the duplex DNA at oriC. Based on these and other results, we conclude that the N-terminal region of the DnaA, protein is involved in the oligomerization of this protein, an essential step for the duplex opening activity at oriC.

Original languageEnglish
Pages (from-to)163-167
Number of pages5
JournalFEMS microbiology letters
Issue number1
Publication statusPublished - 1999 Jul 1



  • DNA replication
  • DnaA
  • N-terminal region
  • Site-directed mutagenesis

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology
  • Genetics

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