View source for 2ijk


==Structure of a Rom protein dimer at 1.55 angstrom resolution==
<StructureSection load='2ijk' size='340' side='right'caption='[[2ijk]], [[Resolution|resolution]] 1.55&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2ijk]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IJK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2IJK FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.55&#8491;</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=2ijk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ijk OCA], [https://pdbe.org/2ijk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ijk RCSB], [https://www.ebi.ac.uk/pdbsum/2ijk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ijk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ROP_ECOLX ROP_ECOLX] Regulates plasmid DNA replication by modulating the initiation of transcription of the primer RNA precursor. Processing of the precursor of the primer, RNAII, is inhibited by hydrogen bonding of RNAII to its complementary sequence in RNAI. ROP increases the affinity of RNAI for RNAII and thus decreases the rate of replication initiation events.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
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    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ij/2ijk_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=2ijk ConSurf].
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== Publication Abstract from PubMed ==
In ColE1, the plasmid encoded RNA one modulator (Rom) protein, which is also referred to as Rop, specifically binds and stabilizes an intermediate RNA loop-loop kissing structure formed between the plasmid encoded transcripts RNA I and RNA II and thereby acts as an auxiliary repressor of replication. Rom folds into a homodimeric, cylindrically packed four helix bundle with an exact twofold symmetry axis (Banner et al., J Mol Biol 1987;196:657-675; Eberle et al., J Biomol 1991;1:71-83). Previous studies (Castagnoli et al., EMBO J 1989;8:621-629; Predki et al., Cell 1995;80:41-50) have localized the RNA binding surface to the H1/H1' face of the helical bundle and found Phe14 to be a key determinant of the binding affinity and specificity for RNA kissing complexes. To investigate the role of Phe14 in RNA recognition, we have determined high-resolution crystal structures of two point mutants of Rom (F14Y and F14W), as well as a high-resolution structure of a crystal form of Rom in which the dimer comprises the asymmetric unit. Although the structures of F14Y and F14W share a very high degree of structural identity with that of the wild-type protein and each other, differences are observed between the three polypeptide chains found in the asymmetric unit of each crystal in the packing of the tryptophan and tyrosine side chains at position 14, as well as some of the other surface exposed side chains of key amino acids involved in RNA binding. In both the wild-type Rom and mutant structures, crystal packing forces can break the exact twofold symmetry of the dimer and influence the conformation of the side chains presented on the H1/H1' face of Rom. Since the new structures show such a high degree of structural identity, the disruption in RNA binding observed for the mutant proteins can be attributed specifically to the chemical nature of the side chain at position 14. Moreover, the fact that even subtle changes in the side chain at position 14 cannot be compensated for by the apparent flexibility of this side chain suggests a highly constrained packing of this residue in the RNA-protein complex. Proteins 2008. (c) 2008 Wiley-Liss, Inc.

New crystal structures of ColE1 Rom and variants resulting from mutation of a surface exposed residue: Implications for RNA-recognition.,Struble EB, Ladner JE, Brabazon DM, Marino JP Proteins. 2008 Feb 7;. PMID:18260113<ref>PMID:18260113</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Rop protein|Rop protein]]
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Struble EB]]