Structural elements of the Streptomyces oriC region and their interactions with the DnaA protein

Microbiology (Reading). 1998 May;144 ( Pt 5):1281-1290. doi: 10.1099/00221287-144-5-1281.


Streptomycetes differ from other prokaryotic organisms in their mycelial life cycle and in possessing a large, linear, GC-rich chromosome. To deduce structural features of the Streptomyces origin of chromosomal replication, the oriC sequences of three Streptomyces species (S. antibioticus, S. chrysomallus and S. lividans) were compared. In Streptomyces, the oriC region contains 19 DnaA boxes whose location, orientation and spacing are conserved. The consensus sequence of the DnaA box identified within Streptomyces oriC is (T/C)(T/C)(G/A/C)TCCACA (preferred bases underlined). The interactions of DnaA with DNA fragments containing single, two or three DnaA boxes were studied using surface plasmon resonance. The dissociation constant (KD) for specific binding of individual DnaA boxes varied between 12 and 78 nM. Streptomyces oriC does not contain the three AT-rich 13-mer direct repeats present in the 5' part of the Escherichia coli oriC region. However, short AT-rich sequences are distributed among the DnaA boxes of Streptomyces oriC. Repeated attempts to unwind Streptomyces oriC have been unsuccessful. It remains to be elucidated whether DnaA interacts with putative accessory proteins which help in unwinding Streptomyces oriC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Cloning, Molecular
  • Consensus Sequence
  • DNA Replication
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Kinetics
  • Molecular Sequence Data
  • Regulatory Sequences, Nucleic Acid
  • Replication Origin*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Streptomyces / chemistry
  • Streptomyces / genetics*
  • Streptomyces / metabolism


  • Bacterial Proteins
  • DNA-Binding Proteins
  • DnaA protein, Bacteria

Associated data

  • GENBANK/AF026792
  • GENBANK/AF027658
  • GENBANK/AF077942