Histone acetyltransferase HBO1 interacts with the ORC1 subunit of the human initiator protein

J Biol Chem. 1999 Aug 13;274(33):23027-34. doi: 10.1074/jbc.274.33.23027.


The origin recognition complex (ORC) is an initiator protein for DNA replication, but also effects transcriptional silencing in Saccharomyces cerevisiae and heterochromatin function in Drosophila. It is not known, however, whether any of these functions of ORC is conserved in mammals. We report the identification of a novel protein, HBO1 (histone acetyltransferase binding to ORC), that interacts with human ORC1 protein, the largest subunit of ORC. HBO1 exists as part of a multisubunit complex that possesses histone H3 and H4 acetyltransferase activities. A fraction of the relatively abundant HBO1 protein associates with ORC1 in human cell extracts. HBO1 is a member of the MYST domain family that includes S. cerevisiae Sas2p, a protein involved in control of transcriptional silencing that also has been genetically linked to ORC function. Thus the interaction between ORC and a MYST domain acetyltransferase is widely conserved. We suggest roles for ORC-mediated acetylation of chromatin in control of both DNA replication and gene expression.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acetyltransferases / chemistry
  • Acetyltransferases / genetics
  • Acetyltransferases / metabolism*
  • Amino Acid Sequence
  • Base Sequence
  • DNA-Binding Proteins / metabolism*
  • HeLa Cells
  • Histone Acetyltransferases
  • Humans
  • Molecular Sequence Data
  • Origin Recognition Complex
  • Protein Binding
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Transcription, Genetic


  • DNA-Binding Proteins
  • ORC1 protein, human
  • Origin Recognition Complex
  • Saccharomyces cerevisiae Proteins
  • Acetyltransferases
  • Histone Acetyltransferases
  • KAT7 protein, human
  • KAT8 protein, human

Associated data

  • GENBANK/AF074606