3d1b: Difference between revisions
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==Tetragonal crystal structure of Tas3 C-terminal alpha motif== | |||
=== | <StructureSection load='3d1b' size='340' side='right' caption='[[3d1b]], [[Resolution|resolution]] 1.70Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3d1b]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Schizosaccharomyces_pombe Schizosaccharomyces pombe]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3D1B OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3D1B FirstGlance]. <br> | |||
</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3d1d|3d1d]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">tas3, SPBC83.03c ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4896 Schizosaccharomyces pombe])</td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3d1b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3d1b OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3d1b RCSB], [http://www.ebi.ac.uk/pdbsum/3d1b PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
RNA interference (RNAi) plays a pivotal role in the formation of heterochromatin at the fission yeast centromeres. The RNA-induced transcriptional silencing (RITS) complex, composed of heterochromatic small interfering RNAs (siRNAs), the siRNA-binding protein Ago1, the chromodomain protein Chp1, and the Ago1/Chp1-interacting protein Tas3, provides a physical tether between the RNAi and heterochromatin assembly pathways. Here, we report the structural and functional characterization of a C-terminal Tas3 alpha-helical motif (TAM), which self-associates into a helical polymer and is required for cis spreading of RITS in centromeric DNA regions. Site-directed mutations of key residues within the hydrophobic monomer-monomer interface disrupt Tas3-TAM polymeric self-association in vitro and result in loss of gene silencing, spreading of RITS, and a dramatic reduction in centromeric siRNAs in vivo. These results demonstrate that, in addition to the chromodomain of Chp1 and siRNA-loaded Ago1, Tas3 self-association is required for RITS spreading and efficient heterochromatic gene silencing at centromeric repeat regions. | |||
An alpha motif at Tas3 C terminus mediates RITS cis spreading and promotes heterochromatic gene silencing.,Li H, Motamedi MR, Yip CK, Wang Z, Walz T, Patel DJ, Moazed D Mol Cell. 2009 Apr 24;34(2):155-67. PMID:19394293<ref>PMID:19394293</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
== | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Schizosaccharomyces pombe]] | [[Category: Schizosaccharomyces pombe]] | ||
[[Category: Li, H | [[Category: Li, H]] | ||
[[Category: Patel, D J | [[Category: Patel, D J]] | ||
[[Category: All alpha motif]] | [[Category: All alpha motif]] | ||
[[Category: Cell cycle]] | [[Category: Cell cycle]] | ||
Revision as of 16:42, 18 December 2014
Tetragonal crystal structure of Tas3 C-terminal alpha motifTetragonal crystal structure of Tas3 C-terminal alpha motif
Structural highlights
Publication Abstract from PubMedRNA interference (RNAi) plays a pivotal role in the formation of heterochromatin at the fission yeast centromeres. The RNA-induced transcriptional silencing (RITS) complex, composed of heterochromatic small interfering RNAs (siRNAs), the siRNA-binding protein Ago1, the chromodomain protein Chp1, and the Ago1/Chp1-interacting protein Tas3, provides a physical tether between the RNAi and heterochromatin assembly pathways. Here, we report the structural and functional characterization of a C-terminal Tas3 alpha-helical motif (TAM), which self-associates into a helical polymer and is required for cis spreading of RITS in centromeric DNA regions. Site-directed mutations of key residues within the hydrophobic monomer-monomer interface disrupt Tas3-TAM polymeric self-association in vitro and result in loss of gene silencing, spreading of RITS, and a dramatic reduction in centromeric siRNAs in vivo. These results demonstrate that, in addition to the chromodomain of Chp1 and siRNA-loaded Ago1, Tas3 self-association is required for RITS spreading and efficient heterochromatic gene silencing at centromeric repeat regions. An alpha motif at Tas3 C terminus mediates RITS cis spreading and promotes heterochromatic gene silencing.,Li H, Motamedi MR, Yip CK, Wang Z, Walz T, Patel DJ, Moazed D Mol Cell. 2009 Apr 24;34(2):155-67. PMID:19394293[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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