View source for 1imq


==COLICIN E9 IMMUNITY PROTEIN IM9, NMR, MINIMIZED AVERAGE STRUCTURE==
<StructureSection load='1imq' size='340' side='right'caption='[[1imq]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1imq]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IMQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1IMQ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1imq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1imq OCA], [https://pdbe.org/1imq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1imq RCSB], [https://www.ebi.ac.uk/pdbsum/1imq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1imq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/IMM9_ECOLX IMM9_ECOLX] This protein is able to protect a cell, which harbors the plasmid ColE9 encoding colicin E9, against colicin E9, it binds specifically to the DNase-type colicin and inhibits its bactericidal activity.
== 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/im/1imq_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=1imq ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The 86-amino acid colicin E9 immunity protein (Im9), which inhibits the DNase activity of colicin E9, has been overexpressed in Escherichia coli and isotopically enriched with 15N and 13C. Using the 3D CBCANH and CBCA(CO)NH experiments, we have almost completely assigned the backbone 13C resonances and extended previously reported 15N/1H backbone assignments [Osborne et al. (1994), Biochemistry 33, 12347-12355]. Side chain assignments for almost all residues were made using the 3D 13C HCCH-TOCSY experiment allied to previous 1H assignments. Sixty solution structures of Im9 were determined using the DIANA program on the basis of 1210 distance restraints and 56 dihedral angle restraints. The 30 lowest-energy structures were then subjected to a slow-cooling simulated annealing protocol using XPLOR and the 21 lowest-energy structures, satisfying the geometric restraints chosen for further analysis. The Im9 structure is well-defined except for the termini and two solvent-exposed loops between residues 28-32 and 57-64. The average RMSD about the average structure of residues 4-84 was 0.94 A for all heavy atoms and 0.53 A for backbone C alpha, C = O, and N atoms. The Im9 fold is novel and can be considered a distorted antiparallel four-helix bundle, in which the third helix is rather short, being terminated close to its N-terminal end by a proline at its C-terminus. The structure fits in well with available kinetic and biochemical data concerning the interaction between Im9 and its target DNase. Important residues of Im9 that govern specificity are located on the molecular surface in a region rich in negatively charged groups, consistent with the proposed electrostatically steered association [Wallis et al. (1995a), Biochemistry 34, 13743-13750].

Three-dimensional solution structure and 13C nuclear magnetic resonance assignments of the colicin E9 immunity protein Im9.,Osborne MJ, Breeze AL, Lian LY, Reilly A, James R, Kleanthous C, Moore GR Biochemistry. 1996 Jul 23;35(29):9505-12. PMID:8755730<ref>PMID:8755730</ref>

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

==See Also==
*[[Colicin immunity protein 3D structures|Colicin immunity protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Breeze AL]]
[[Category: James R]]
[[Category: Kleanthous C]]
[[Category: Lian LY]]
[[Category: Moore GR]]
[[Category: Osborne MJ]]
[[Category: Reilly A]]