1m4z
Crystal structure of the N-terminal BAH domain of Orc1p
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| , resolution 2.2Å | |||||||
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| Ligands: | |||||||
| Gene: | Orc1 (Saccharomyces cerevisiae) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
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.
About this StructureAbout this Structure
1M4Z is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
ReferenceReference
Structure and function of the BAH-containing domain of Orc1p in epigenetic silencing., Zhang Z, Hayashi MK, Merkel O, Stillman B, Xu RM, EMBO J. 2002 Sep 2;21(17):4600-11. PMID:12198162
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