Structural Basis for the Unique Multivalent Readout of Unmodified H3 Tail by Arabidopsis ORC1b BAH-PHD Cassette

Structure. 2016 Mar 1;24(3):486-94. doi: 10.1016/j.str.2016.01.004. Epub 2016 Feb 11.

Abstract

DNA replication initiation relies on the formation of the origin recognition complex (ORC). The plant ORC subunit 1 (ORC1) protein possesses a conserved N-terminal BAH domain with an embedded plant-specific PHD finger, whose function may be potentially regulated by an epigenetic mechanism. Here, we report structural and biochemical studies on the Arabidopsis thaliana ORC1b BAH-PHD cassette which specifically recognizes the unmodified H3 tail. The crystal structure of ORC1b BAH-PHD cassette in complex with an H3(1-15) peptide reveals a strict requirement for the unmodified state of R2, T3, and K4 on the H3 tail and a novel multivalent BAH and PHD readout mode for H3 peptide recognition. Such recognition may contribute to epigenetic regulation of the initiation of DNA replication.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / chemistry
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / chemistry*
  • Arabidopsis Proteins / metabolism*
  • Binding Sites
  • Cell Cycle Proteins / chemistry*
  • Cell Cycle Proteins / metabolism*
  • DNA Replication
  • Epigenesis, Genetic
  • Histones / metabolism
  • Models, Molecular
  • Peptides / metabolism*
  • Protein Binding
  • Protein Domains

Substances

  • Arabidopsis Proteins
  • Cell Cycle Proteins
  • Histones
  • ORC1b protein, Arabidopsis
  • Peptides