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| | ==Structure of the E. coli MacB ABC domain (P6122)== | | ==Structure of the E. coli MacB ABC domain (P6122)== |
| - | <StructureSection load='5lja' size='340' side='right' caption='[[5lja]], [[Resolution|resolution]] 2.40Å' scene=''> | + | <StructureSection load='5lja' size='340' side='right'caption='[[5lja]], [[Resolution|resolution]] 2.40Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5lja]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5LJA OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5LJA FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5lja]] is a 1 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=5LJA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5LJA FirstGlance]. <br> |
| - | </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=5lja FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5lja OCA], [http://pdbe.org/5lja PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5lja RCSB], [http://www.ebi.ac.uk/pdbsum/5lja PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5lja ProSAT]</span></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4Å</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=5lja FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5lja OCA], [https://pdbe.org/5lja PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5lja RCSB], [https://www.ebi.ac.uk/pdbsum/5lja PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5lja ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/MACB_ECOLI MACB_ECOLI]] Part of the tripartite efflux system MacAB-TolC. MacB is a non-canonical ABC transporter that contains transmembrane domains (TMD), which form a pore in the inner membrane, and an ATP-binding domain (NBD), which is responsible for energy generation. When overexpressed, the system confers resistance against macrolides composed of 14- and 15-membered lactones but no or weak resistance against 16-membered ones. In addition, the system could also transport R-LPS or a similar glycolipid.<ref>PMID:11544226</ref> <ref>PMID:17214741</ref> <ref>PMID:18955484</ref> <ref>PMID:23974027</ref> | + | [https://www.uniprot.org/uniprot/MACB_ECOLI MACB_ECOLI] Part of the tripartite efflux system MacAB-TolC. MacB is a non-canonical ABC transporter that contains transmembrane domains (TMD), which form a pore in the inner membrane, and an ATP-binding domain (NBD), which is responsible for energy generation. When overexpressed, the system confers resistance against macrolides composed of 14- and 15-membered lactones but no or weak resistance against 16-membered ones. In addition, the system could also transport R-LPS or a similar glycolipid.<ref>PMID:11544226</ref> <ref>PMID:17214741</ref> <ref>PMID:18955484</ref> <ref>PMID:23974027</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Crow, A]] | + | [[Category: Escherichia coli K-12]] |
| - | [[Category: Membrane protein abc transporter]] | + | [[Category: Large Structures]] |
| - | [[Category: Transport protein]] | + | [[Category: Crow A]] |
| Structural highlights
Function
MACB_ECOLI Part of the tripartite efflux system MacAB-TolC. MacB is a non-canonical ABC transporter that contains transmembrane domains (TMD), which form a pore in the inner membrane, and an ATP-binding domain (NBD), which is responsible for energy generation. When overexpressed, the system confers resistance against macrolides composed of 14- and 15-membered lactones but no or weak resistance against 16-membered ones. In addition, the system could also transport R-LPS or a similar glycolipid.[1] [2] [3] [4]
Publication Abstract from PubMed
MacB is an ABC transporter that collaborates with the MacA adaptor protein and TolC exit duct to drive efflux of antibiotics and enterotoxin STII out of the bacterial cell. Here we present the structure of ATP-bound MacB and reveal precise molecular details of its mechanism. The MacB transmembrane domain lacks a central cavity through which substrates could be passed, but instead conveys conformational changes from one side of the membrane to the other, a process we term mechanotransmission. Comparison of ATP-bound and nucleotide-free states reveals how reversible dimerization of the nucleotide binding domains drives opening and closing of the MacB periplasmic domains via concerted movements of the second transmembrane segment and major coupling helix. We propose that the assembled tripartite pump acts as a molecular bellows to propel substrates through the TolC exit duct, driven by MacB mechanotransmission. Homologs of MacB that do not form tripartite pumps, but share structural features underpinning mechanotransmission, include the LolCDE lipoprotein trafficking complex and FtsEX cell division signaling protein. The MacB architecture serves as the blueprint for understanding the structure and mechanism of an entire ABC transporter superfamily and the many diverse functions it supports.
Structure and mechanotransmission mechanism of the MacB ABC transporter superfamily.,Crow A, Greene NP, Kaplan E, Koronakis V Proc Natl Acad Sci U S A. 2017 Nov 6. pii: 201712153. doi:, 10.1073/pnas.1712153114. PMID:29109272[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kobayashi N, Nishino K, Yamaguchi A. Novel macrolide-specific ABC-type efflux transporter in Escherichia coli. J Bacteriol. 2001 Oct;183(19):5639-44. PMID:11544226 doi:http://dx.doi.org/10.1128/JB.183.19.5639-5644.2001
- ↑ Tikhonova EB, Devroy VK, Lau SY, Zgurskaya HI. Reconstitution of the Escherichia coli macrolide transporter: the periplasmic membrane fusion protein MacA stimulates the ATPase activity of MacB. Mol Microbiol. 2007 Feb;63(3):895-910. Epub 2007 Jan 4. PMID:17214741 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05549.x
- ↑ Lin HT, Bavro VN, Barrera NP, Frankish HM, Velamakanni S, van Veen HW, Robinson CV, Borges-Walmsley MI, Walmsley AR. MacB ABC transporter is a dimer whose ATPase activity and macrolide-binding capacity are regulated by the membrane fusion protein MacA. J Biol Chem. 2009 Jan 9;284(2):1145-54. doi: 10.1074/jbc.M806964200. Epub 2008, Oct 27. PMID:18955484 doi:http://dx.doi.org/10.1074/jbc.M806964200
- ↑ Lu S, Zgurskaya HI. MacA, a periplasmic membrane fusion protein of the macrolide transporter MacAB-TolC, binds lipopolysaccharide core specifically and with high affinity. J Bacteriol. 2013 Nov;195(21):4865-72. doi: 10.1128/JB.00756-13. Epub 2013 Aug, 23. PMID:23974027 doi:http://dx.doi.org/10.1128/JB.00756-13
- ↑ Crow A, Greene NP, Kaplan E, Koronakis V. Structure and mechanotransmission mechanism of the MacB ABC transporter superfamily. Proc Natl Acad Sci U S A. 2017 Nov 6. pii: 201712153. doi:, 10.1073/pnas.1712153114. PMID:29109272 doi:http://dx.doi.org/10.1073/pnas.1712153114
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