1M4Z

Crystal structure of the N-terminal BAH domain of Orc1p

Summary for 1M4Z

• Entry DOI: 10.2210/pdb1m4z/pdb
• Descriptor: ORIGIN RECOGNITION COMPLEX SUBUNIT 1, MANGANESE (II) ION (3 entities in total)
• Functional Keywords: dna replication, transcriptional silencing, chromatin, bah domain, gene regulation
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Cellular location: Nucleus: P54784
• Total number of polymer chains: 2
• Total formula weight: 55399.83

Authors

Zhang, Z.,Hayashi, M.K.,Merkel, O.,Stillman, B.,Xu, R.-M. (deposition date: 2002-07-05, release date: 2002-09-11, Last modification date: 2024-02-14)

Primary citation

Zhang, Z.,Hayashi, M.K.,Merkel, O.,Stillman, B.,Xu, R.M.
Structure and function of the BAH-containing domain of Orc1p in epigenetic silencing.
EMBO J., 21:4600-4611, 2002

PubMed Abstract: The N-terminal domain of the largest subunit of the Saccharomyces cerevisiae origin recognition complex (Orc1p) functions in transcriptional silencing and contains a bromo-adjacent homology (BAH) domain found in some chromatin-associated proteins including Sir3p. The 2.2 A crystal structure of the N-terminal domain of Orc1p revealed a BAH core and a non-conserved helical sub-domain. Mutational analyses demonstrated that the helical sub-domain was necessary and sufficient to bind Sir1p, and critical for targeting Sir1p primarily to the cis-acting E silencers at the HMR and HML silent chromatin domains. In the absence of the BAH domain, approximately 14-20% of cells in a population were silenced at the HML locus. Moreover, the distributions of the Sir2p, Sir3p and Sir4p proteins, while normal, were at levels lower than found in wild-type cells. Thus, in the absence of the Orc1p BAH domain, HML resembled silencing of genes adjacent to telomeres. These data are consistent with the view that the Orc1p-Sir1p interaction at the E silencers ensures stable inheritance of pre-established Sir2p, Sir3p and Sir4p complexes at the silent mating type loci.

PubMed: 12198162
DOI: 10.1093/emboj/cdf468

Experimental method

X-RAY DIFFRACTION (2.2 Å)