View source for 1tlh


==T4 AsiA bound to sigma70 region 4==
<StructureSection load='1tlh' size='340' side='right'caption='[[1tlh]], [[NMR_Ensembles_of_Models | 20 NMR models]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1tlh]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895] and [http://en.wikipedia.org/wiki/Bpt4 Bpt4]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TLH OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1TLH FirstGlance]. <br>
</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1tkv|1tkv]], [[1tl6|1tl6]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ASIA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10665 BPT4]), RPOD, ALT, B3067 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1tlh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tlh OCA], [http://pdbe.org/1tlh PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1tlh RCSB], [http://www.ebi.ac.uk/pdbsum/1tlh PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1tlh ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/ASIA_BPT4 ASIA_BPT4]] Transcriptional inhibitor. Inhibits sigma 70-directed transcription by weakening its interaction with the core of the host's RNA polymerase. This allows Gp55 to successfully compete for the core enzyme. Plays an important role during the prereplicative period of phage T4 development.<ref>PMID:8021178</ref> <ref>PMID:15257291</ref>  [[http://www.uniprot.org/uniprot/RPOD_ECOLI RPOD_ECOLI]] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This is the primary sigma factor of this bacterium. 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/tl/1tlh_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1tlh ConSurf].
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<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Bacteriophage T4 AsiA is a versatile transcription factor capable of inhibiting host gene expression as an 'anti-sigma' factor while simultaneously promoting gene-specific expression of T4 middle genes in conjunction with T4 MotA. To accomplish this task, AsiA engages conserved region 4 of Eschericia coli sigma70, blocking recognition of most host promoters by sequestering the DNA-binding surface at the AsiA/sigma70 interface. The three-dimensional structure of an AsiA/region 4 complex reveals that the C-terminal alpha helix of region 4 is unstructured, while four other helices adopt a completely different conformation relative to the canonical structure of unbound region 4. That AsiA induces, rather than merely stabilizes, this rearrangement can be realized by comparison to the homologous structures of region 4 solved in a variety of contexts, including the structure of Thermotoga maritima sigmaA region 4 described herein. AsiA simultaneously occupies the surface of region 4 that ordinarily contacts core RNA polymerase (RNAP), suggesting that an AsiA-bound sigma70 may also undergo conformational changes in the context of the RNAP holoenzyme.

T4 AsiA blocks DNA recognition by remodeling sigma70 region 4.,Lambert LJ, Wei Y, Schirf V, Demeler B, Werner MH EMBO J. 2004 Aug 4;23(15):2952-62. Epub 2004 Jul 15. PMID:15257291<ref>PMID:15257291</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1tlh" style="background-color:#fffaf0;"></div>

==See Also==
*[[Sigma factor 3D structures|Sigma factor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus coli migula 1895]]
[[Category: Bpt4]]
[[Category: Large Structures]]
[[Category: Demeler, B]]
[[Category: Lambert, L J]]
[[Category: Schirf, V]]
[[Category: Wei, Y]]
[[Category: Werner, M H]]
[[Category: Anti-sigma]]
[[Category: Rna polymerase]]
[[Category: Sigma70]]
[[Category: Transcription]]