7cei: Difference between revisions
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==THE ENDONUCLEASE DOMAIN OF COLICIN E7 IN COMPLEX WITH ITS INHIBITOR IM7 PROTEIN== | |||
<StructureSection load='7cei' size='340' side='right' caption='[[7cei]], [[Resolution|resolution]] 2.30Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[7cei]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli_str._k-12_substr._w3110 Escherichia coli str. k-12 substr. w3110]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7CEI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=7CEI FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CEIE7 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=316407 Escherichia coli str. K-12 substr. W3110])</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=7cei FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7cei OCA], [http://www.rcsb.org/pdb/explore.do?structureId=7cei RCSB], [http://www.ebi.ac.uk/pdbsum/7cei PDBsum]</span></td></tr> | |||
</table> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/CEA7_ECOLI CEA7_ECOLI]] This plasmid-coded bactericidal protein is an endonuclease active on both single- and double-stranded DNA but with undefined specificity. Colicins are polypeptide toxins produced by and active against E.coli and closely related bacteria. | |||
== 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/ce/7cei_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/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
BACKGROUND: Colicin E7 (ColE7) is one of the bacterial toxins classified as a DNase-type E-group colicin. The cytotoxic activity of a colicin in a colicin-producing cell can be counteracted by binding of the colicin to a highly specific immunity protein. This biological event is a good model system for the investigation of protein recognition. RESULTS: The crystal structure of a one-to-one complex between the DNase domain of colicin E7 and its cognate immunity protein Im7 has been determined at 2.3 A resolution. Im7 in the complex is a varied four-helix bundle that is identical to the structure previously determined for uncomplexed Im7. The structure of the DNase domain of ColE7 displays a novel alpha/beta fold and contains a Zn2+ ion bound to three histidine residues and one water molecule in a distorted tetrahedron geometry. Im7 has a V-shaped structure, extending two arms to clamp the DNase domain of ColE7. One arm (alpha1(*)-loop12-alpha2(*); where * represents helices in Im7) is located in the region that displays the greatest sequence variation among members of the immunity proteins in the same subfamily. This arm mainly uses acidic sidechains to interact with the basic sidechains in the DNase domain of ColE7. The other arm (loop 23-alpha3(*)-loop 34) is more conserved and it interacts not only with the sidechain but also with the mainchain atoms of the DNase domain of ColE7. CONCLUSIONS: The protein interfaces between the DNase domain of ColE7 and Im7 are charge-complementary and charge interactions contribute significantly to the tight and specific binding between the two proteins. The more variable arm in Im7 dominates the binding specificity of the immunity protein to its cognate colicin. Biological and structural data suggest that the DNase active site for ColE7 is probably near the metal-binding site. | |||
The crystal structure of the DNase domain of colicin E7 in complex with its inhibitor Im7 protein.,Ko TP, Liao CC, Ku WY, Chak KF, Yuan HS Structure. 1999 Jan 15;7(1):91-102. PMID:10368275<ref>PMID:10368275</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
| Line 13: | Line 35: | ||
*[[Directed evolution|Directed evolution]] | *[[Directed evolution|Directed evolution]] | ||
*[[Im7|Im7]] | *[[Im7|Im7]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Escherichia coli str. k-12 substr. w3110]] | [[Category: Escherichia coli str. k-12 substr. w3110]] | ||
[[Category: Chak, K F | [[Category: Chak, K F]] | ||
[[Category: Ko, T P | [[Category: Ko, T P]] | ||
[[Category: Ku, W Y | [[Category: Ku, W Y]] | ||
[[Category: Liao, C C | [[Category: Liao, C C]] | ||
[[Category: Yuan, H S | [[Category: Yuan, H S]] | ||
[[Category: Dnase]] | [[Category: Dnase]] | ||
[[Category: E-group colicin]] | [[Category: E-group colicin]] | ||