3fpp

Structural highlights

Function

MACA_ECOLI Part of the tripartite efflux system MacAB-TolC. MacA stimulates the ATPase activity of MacB by promoting the closed ATP-bound state of MacB, increases the capacity of MacB to bind macrolides such as erythromycin, and provides a physical link between MacB and TolC. 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, MacA binds tightly rough-core lipopolysaccharide (R-LPS), suggesting that the system could also transport R-LPS or a similar glycolipid.^{[1] [2] [3] [4] [5]}

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

References

1. ↑ 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
2. ↑ 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
3. ↑ 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
4. ↑ Modali SD, Zgurskaya HI. The periplasmic membrane proximal domain of MacA acts as a switch in stimulation of ATP hydrolysis by MacB transporter. Mol Microbiol. 2011 Aug;81(4):937-51. doi: 10.1111/j.1365-2958.2011.07744.x. Epub, 2011 Jul 4. PMID:21696464 doi:http://dx.doi.org/10.1111/j.1365-2958.2011.07744.x
5. ↑ 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