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Title: Structure and Function of the Saccharomyces Cerevisiae Sir3 BAH Domain

Abstract

Previous work has shown that the N terminus of the Saccharomyces cerevisiae Sir3 protein is crucial for the function of Sir3 in transcriptional silencing. Here, we show that overexpression of N-terminal fragments of Sir3 in strains lacking the full-length protein can lead to some silencing of HML and HMR. Sir3 contains a BAH (bromo-adjacent homology) domain at its N terminus. Overexpression of this domain alone can lead to silencing as long as Sir1 is overexpressed and Sir2 and Sir4 are present. Overexpression of the closely related Orc1 BAH domain can also silence in the absence of any Sir3 protein. A previously characterized hypermorphic sir3 mutation, D205N, greatly improves silencing by the Sir3 BAH domain and allows it to bind to DNA and oligonucleosomes in vitro. A previously uncharacterized region in the Sir1 N terminus is required for silencing by both the Sir3 and Orc1 BAH domains. The structure of the Sir3 BAH domain has been determined. In the crystal, the molecule multimerizes in the form of a left-handed superhelix. This superhelix may be relevant to the function of the BAH domain of Sir3 in silencing.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
930572
Report Number(s):
BNL-80753-2008-JA
Journal ID: ISSN 0270-7306; MCEBD4; TRN: US200904%%792
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Molecular and Cellular Biology; Journal Volume: 26; Journal Issue: 8
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CRYSTAL STRUCTURE; DNA; IN VITRO; PROTEINS; SACCHAROMYCES CEREVISIAE; STRAINS; national synchrotron light source

Citation Formats

Connelly,J., Yuan, P., Hsu, H., Li, Z., Xu, R., and Sternglanz, R. Structure and Function of the Saccharomyces Cerevisiae Sir3 BAH Domain. United States: N. p., 2006. Web. doi:10.1128/MCB.26.8.3256-3265.2006.
Connelly,J., Yuan, P., Hsu, H., Li, Z., Xu, R., & Sternglanz, R. Structure and Function of the Saccharomyces Cerevisiae Sir3 BAH Domain. United States. doi:10.1128/MCB.26.8.3256-3265.2006.
Connelly,J., Yuan, P., Hsu, H., Li, Z., Xu, R., and Sternglanz, R. Sun . "Structure and Function of the Saccharomyces Cerevisiae Sir3 BAH Domain". United States. doi:10.1128/MCB.26.8.3256-3265.2006.
@article{osti_930572,
title = {Structure and Function of the Saccharomyces Cerevisiae Sir3 BAH Domain},
author = {Connelly,J. and Yuan, P. and Hsu, H. and Li, Z. and Xu, R. and Sternglanz, R.},
abstractNote = {Previous work has shown that the N terminus of the Saccharomyces cerevisiae Sir3 protein is crucial for the function of Sir3 in transcriptional silencing. Here, we show that overexpression of N-terminal fragments of Sir3 in strains lacking the full-length protein can lead to some silencing of HML and HMR. Sir3 contains a BAH (bromo-adjacent homology) domain at its N terminus. Overexpression of this domain alone can lead to silencing as long as Sir1 is overexpressed and Sir2 and Sir4 are present. Overexpression of the closely related Orc1 BAH domain can also silence in the absence of any Sir3 protein. A previously characterized hypermorphic sir3 mutation, D205N, greatly improves silencing by the Sir3 BAH domain and allows it to bind to DNA and oligonucleosomes in vitro. A previously uncharacterized region in the Sir1 N terminus is required for silencing by both the Sir3 and Orc1 BAH domains. The structure of the Sir3 BAH domain has been determined. In the crystal, the molecule multimerizes in the form of a left-handed superhelix. This superhelix may be relevant to the function of the BAH domain of Sir3 in silencing.},
doi = {10.1128/MCB.26.8.3256-3265.2006},
journal = {Molecular and Cellular Biology},
number = 8,
volume = 26,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
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