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The Outer membrane efflux protein (OEP) Family [Function: Biogenesis/Secretion] Seed alignment | Full alignment | Pfam page | Pfam Wiki page | TC-DB page

Proteins of this family participate mainly in the type I secretion pathway (Sec-independent), functioning in conjunction with cytoplasmic membrane transporters of various families (like MFS, ABC, RND and PET) and periplasmic proteins. The complex formed in this way, allows the export of various solutes (metals, drugs, proteins) across the two envelopes of the Gram-negative bacterial cell envelope in a single energy-coupled step. The crystal structure of Escherichia coli TolC has been solved. 3 TolC monomers form a continuous channel with length over 140 Å spanning both the outer membrane with a ß-barrel of 12 ß strands (4 per monomer) and the periplasmic space (with 12 coil-coiled alpha helices). Similar structure has been observed in the VceC of Vibrio cholerae, and it is assumed for other members of the family (OprN, OprM etc). Such proteins are found in nearly all classes of Proteobacteria, in Cyanobacteria, Spirochetes and in species of Deinococcus, Aquifex and Porphyromonas. Due to their multimeric nature, prediction algorithms are not so successful in proteins of this family.

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Literature references

Discovery of Novel Leptospirosis Vaccine Candidates Using Reverse and Structural Vaccinology
Front Immunol. 2017 Apr 27;8:463. doi: 10.3389/fimmu.2017.00463. eCollection 2017.
PMID: 28496441

Crystal structures of OprN and OprJ, outer membrane factors of multidrug tripartite efflux pumps of Pseudomonas aeruginosa
Proteins. 2016 Jun;84(6):759-69. doi: 10.1002/prot.25022. Epub 2016 Mar 9.
PMID: 26914226

New OprM structure highlighting the nature of the N-terminal anchor
Front Microbiol. 2015 Jul 1;6:667. doi: 10.3389/fmicb.2015.00667. eCollection 2015.
PMID: 26191054

Assembly and stability of Salmonella enterica ser. Typhi TolC protein in POPE and DMPE
J Biol Phys. 2014 Sep;40(4):387-400. doi: 10.1007/s10867-014-9357-9. Epub 2014 Jul 11.
PMID: 25011632

Structure of the periplasmic adaptor protein from a major facilitator superfamily (MFS) multidrug efflux pump
FEBS Lett. 2014 Aug 25;588(17):3147-53. doi: 10.1016/j.febslet.2014.06.055. Epub 2014 Jul 1.
PMID: 24996185

Genetic assessment of the role of AcrB ß-hairpins in the assembly of the TolC-AcrAB multidrug efflux pump of Escherichia coli
Mol Microbiol. 2014 Mar;91(5):965-75. doi: 10.1111/mmi.12508. Epub 2014 Jan 21.
PMID: 24386963

Structure-function analysis of the ATP-driven glycolipid efflux pump DevBCA reveals complex organization with TolC/HgdD
FEBS Lett. 2014 Jan 31;588(3):395-400. doi: 10.1016/j.febslet.2013.12.004. Epub 2013 Dec 17.
PMID: 24361095

Structure of an atypical periplasmic adaptor from a multidrug efflux pump of the spirochete Borrelia burgdorferi
FEBS Lett. 2013 Sep 17;587(18):2984-8. doi: 10.1016/j.febslet.2013.06.056. Epub 2013 Jul 10.
PMID: 23851070

Tat pathway-mediated translocation of the Sec pathway substrate OprM, an outer membrane subunit of the resistance nodulation division xenobiotic extrusion pumps, in Pseudomonas Aeruginosa
Chemotherapy. 2013;59(2):129-37. doi: 10.1159/000353894. Epub 2013 Sep 18.
PMID: 24051688

Gating and conduction of nano-channel forming proteins: a computational approach
J Biomol Struct Dyn. 2013;31(8):818-28. doi: 10.1080/07391102.2012.712460. Epub 2012 Aug 28.
PMID: 22928968

Activity monitoring of functional OprM using a biomimetic microfluidic device
Analyst. 2012 Feb 21;137(4):847-52. doi: 10.1039/c2an16007b. Epub 2012 Jan 4.
PMID: 22215439

Trimeric structure of OprN and OprM efflux proteins from Pseudomonas aeruginosa, by 2D electron crystallography
J Struct Biol. 2005 Apr;150(1):50-7. doi: 10.1016/j.jsb.2005.01.001.
PMID: 15797729

The crystal structure of the outer membrane protein VceC from the bacterial pathogen Vibrio cholerae at 1.8 A resolution
J Biol Chem. 2005 Apr 15;280(15):15307-14. doi: 10.1074/jbc.M500401200. Epub 2005 Jan 31.
PMID: 15684414

Three's company: component structures bring a closer view of tripartite drug efflux pumps
Curr Opin Struct Biol. 2004 Dec;14(6):741-7. doi: 10.1016/
PMID: 15582398

Type I secretion in gram-negative bacteria
Biochim Biophys Acta. 2004 Nov 11;1694(1-3):149-61. doi: 10.1016/j.bbamcr.2004.05.001.
PMID: 15546664

Structure and function of TolC: the bacterial exit duct for proteins and drugs
Annu Rev Biochem. 2004;73:467-89. doi: 10.1146/annurev.biochem.73.011303.074104.
PMID: 15189150

Proteins in this family with 3D-structure
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