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[[Image:2xmx.jpg|left|200px]]


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==High resolution structure of Colicin M==
The line below this paragraph, containing "STRUCTURE_2xmx", creates the "Structure Box" on the page.
<StructureSection load='2xmx' size='340' side='right'caption='[[2xmx]], [[Resolution|resolution]] 1.67&Aring;' scene=''>
You may change the PDB parameter (which sets the PDB file loaded into the applet)  
== Structural highlights ==
or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
<table><tr><td colspan='2'>[[2xmx]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2XMX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2XMX FirstGlance]. <br>
or leave the SCENE parameter empty for the default display.
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.67&#8491;</td></tr>
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<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO3:CARBONATE+ION'>CO3</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>
{{STRUCTURE_2xmx|  PDB=2xmx  |  SCENE=  }}
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2xmx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xmx OCA], [https://pdbe.org/2xmx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2xmx RCSB], [https://www.ebi.ac.uk/pdbsum/2xmx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2xmx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CEAM_ECOLX CEAM_ECOLX] Colicins are polypeptide toxins produced by and active against E.coli and closely related bacteria.  This is a calcium-requiring inhibitor for murein biosynthesis; it causes lysis of sensitive cells accompanied by murein degradation. The target site is possibly the cytoplasmic membrane.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Colicin M (Cma) is specifically imported into the periplasm of Escherichia coli and kills the cells. Killing depends on the periplasmic peptidyl prolyl cis-trans isomerase (PPIase)/chaperone FkpA. To identify the Cma prolyl bonds targeted by FkpA, we replaced the 15 proline residues individually with alanine. Nine mutant proteins were fully active; Cma(P129A), Cma(P176A), and Cma(P260A) displayed 1% and Cma(P107A) 10% of the wild-type activity. Cma(P107A), Cma(P129A), and Cma(P260A) but not Cma(P176A) killed cells after entering the periplasm via osmotic shock, indicating that the former mutants were translocation deficient; Cma(P129A) did not bind to the FhuA outer membrane receptor. The crystal structures of Cma and Cma(P176A) were identical, excluding inactivation of the activity domain located far from P176. In a new PPIase assay, FkpA isomerized the Cma prolyl bond in peptide FP(176) at a high rate but KP(107) and LP(260) at only &lt;10% of that rate. The four mutant proteins secreted into the periplasm via a fused signal sequence were toxic but much less than wild-type Cma. Wild-type and mutant Cma proteins secreted or translocated across the outer membrane by energy-coupled import or unspecific osmotic shock were only active in the presence of FkpA. We propose that Cma unfolds during transfer across the outer or cytoplasmic membrane and refolds to the active form in the periplasm assisted by FkpA. Weak refolding of Cma(P176A) would explain its low activity in all assays. Of the four proline residues identified as being important for Cma activity, FP(176) is most likely targeted by FkpA.


===HIGH RESOLUTION STRUCTURE OF COLICIN M===
Activation of colicin M by the FkpA prolyl cis-trans isomerase/chaperone.,Helbig S, Patzer SI, Schiene-Fischer C, Zeth K, Braun V J Biol Chem. 2010 Dec 13. PMID:21149455<ref>PMID:21149455</ref>


From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2xmx" style="background-color:#fffaf0;"></div>


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==See Also==
The line below this paragraph, {{ABSTRACT_PUBMED_21149455}}, adds the Publication Abstract to the page
*[[Colicin 3D structures|Colicin 3D structures]]
(as it appears on PubMed at http://www.pubmed.gov), where 21149455 is the PubMed ID number.
== References ==
-->
<references/>
{{ABSTRACT_PUBMED_21149455}}
__TOC__
 
</StructureSection>
==About this Structure==
[[Category: Escherichia coli K-12]]
[[2xmx]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2XMX OCA].
[[Category: Large Structures]]
 
[[Category: Albrecht R]]
==Reference==
[[Category: Braun V]]
<ref group="xtra">PMID:21149455</ref><references group="xtra"/>
[[Category: Patzer SI]]
[[Category: Escherichia coli]]
[[Category: Zeth K]]
[[Category: Albrecht, R.]]
[[Category: Braun, V.]]
[[Category: Patzer, S I.]]
[[Category: Zeth, K.]]
[[Category: Antibiotic]]
[[Category: Antimicrobial protein]]
[[Category: Bacteriocin]]
[[Category: Phosphatase]]
[[Category: Tonb box]]

Latest revision as of 13:34, 20 December 2023

High resolution structure of Colicin MHigh resolution structure of Colicin M

Structural highlights

2xmx is a 2 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.67Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CEAM_ECOLX Colicins are polypeptide toxins produced by and active against E.coli and closely related bacteria. This is a calcium-requiring inhibitor for murein biosynthesis; it causes lysis of sensitive cells accompanied by murein degradation. The target site is possibly the cytoplasmic membrane.

Publication Abstract from PubMed

Colicin M (Cma) is specifically imported into the periplasm of Escherichia coli and kills the cells. Killing depends on the periplasmic peptidyl prolyl cis-trans isomerase (PPIase)/chaperone FkpA. To identify the Cma prolyl bonds targeted by FkpA, we replaced the 15 proline residues individually with alanine. Nine mutant proteins were fully active; Cma(P129A), Cma(P176A), and Cma(P260A) displayed 1% and Cma(P107A) 10% of the wild-type activity. Cma(P107A), Cma(P129A), and Cma(P260A) but not Cma(P176A) killed cells after entering the periplasm via osmotic shock, indicating that the former mutants were translocation deficient; Cma(P129A) did not bind to the FhuA outer membrane receptor. The crystal structures of Cma and Cma(P176A) were identical, excluding inactivation of the activity domain located far from P176. In a new PPIase assay, FkpA isomerized the Cma prolyl bond in peptide FP(176) at a high rate but KP(107) and LP(260) at only <10% of that rate. The four mutant proteins secreted into the periplasm via a fused signal sequence were toxic but much less than wild-type Cma. Wild-type and mutant Cma proteins secreted or translocated across the outer membrane by energy-coupled import or unspecific osmotic shock were only active in the presence of FkpA. We propose that Cma unfolds during transfer across the outer or cytoplasmic membrane and refolds to the active form in the periplasm assisted by FkpA. Weak refolding of Cma(P176A) would explain its low activity in all assays. Of the four proline residues identified as being important for Cma activity, FP(176) is most likely targeted by FkpA.

Activation of colicin M by the FkpA prolyl cis-trans isomerase/chaperone.,Helbig S, Patzer SI, Schiene-Fischer C, Zeth K, Braun V J Biol Chem. 2010 Dec 13. PMID:21149455[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. ↑ Helbig S, Patzer SI, Schiene-Fischer C, Zeth K, Braun V. Activation of colicin M by the FkpA prolyl cis-trans isomerase/chaperone. J Biol Chem. 2010 Dec 13. PMID:21149455 doi:10.1074/jbc.M110.165274

2xmx, resolution 1.67Å

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