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Escherichia coli K-12 substr. MG1655 Polypeptide: MacAB-TolC macrolide efflux transport system - membrane fusion protein



Gene: macA Accession Numbers: G6461 (EcoCyc), b0878, ECK0869

Synonyms: ybjY

Regulation Summary Diagram: ?

Regulation summary diagram for macA

Component of: MacAB-TolC macrolide efflux transport system (extended summary available)

Summary:
MacA is a peripheral membrane protein of the MFP family and a component of the MacAB macrolide efflux transporter complex. The crystal structure of MacA has been determined at 3.0Å resolution. MacA exists as a hexamer in vitro and in vivo and forms a funnel-like structure with a central channel [Yum09]. A non-cleavable signal-like sequence anchors MacA to the inner membrane [Kobayashi01a, Tikhonova07]. MacA interacts with MacB and with TolC. MacA stimulates the ATPase activity of MacB when reconstituted into proteoliposomes and in E. coli membrane vesicles [Tikhonova07]. Binding of MacA to MacB stabilises the ATP bound conformation of MacB [Modali11].

Gene Citations: [Kobayashi01b, Maciag11]

Locations: inner membrane

Map Position: [918,458 -> 919,573] (19.8 centisomes, 71°)
Length: 1116 bp / 371 aa

Molecular Weight of Polypeptide: 40.624 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0002986 , DIP:DIP-11460N , EchoBASE:EB3458 , EcoGene:EG13694 , EcoliWiki:b0878 , ModBase:P75830 , OU-Microarray:b0878 , PortEco:macA , PR:PRO_000023144 , Pride:P75830 , Protein Model Portal:P75830 , RefSeq:NP_415399 , RegulonDB:G6461 , SMR:P75830 , String:511145.b0878 , UniProt:P75830

Relationship Links: InterPro:IN-FAMILY:IPR006143 , InterPro:IN-FAMILY:IPR030190 , Panther:IN-FAMILY:PTHR30572:SF3 , PDB:Structure:3FPP , Pfam:IN-FAMILY:PF00529

In Paralogous Gene Group: 132 (13 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0046618 - drug export Inferred from experiment [Kobayashi01a]
GO:0006810 - transport Inferred by computational analysis [UniProtGOA11, GOA01]
GO:0046677 - response to antibiotic Inferred by computational analysis [UniProtGOA11]
GO:0055085 - transmembrane transport Inferred by computational analysis [GOA01]
Molecular Function: GO:0005515 - protein binding Inferred from experiment [Lin09]
GO:0022891 - substrate-specific transmembrane transporter activity Inferred from experiment Inferred by computational analysis [GOA01, Kobayashi01a]
GO:0042802 - identical protein binding Inferred from experiment [Yum09]
Cellular Component: GO:0005886 - plasma membrane Inferred from experiment Inferred by computational analysis [UniProtGOA11a, UniProtGOA11, DiazMejia09, LopezCampistrou05]
GO:0019898 - extrinsic component of membrane Inferred from experiment Inferred by computational analysis [GOA01, Kobayashi01a]
GO:0016020 - membrane Inferred by computational analysis [UniProtGOA11, GOA01]
GO:0016021 - integral component of membrane Inferred by computational analysis [UniProtGOA11]

MultiFun Terms: cell structure membrane
transport Accessory Factors Involved in Transport

Essentiality data for macA knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB enriched Yes 37 Aerobic 6.95   Yes [Gerdes03, Comment 1]
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 2]
M9 medium with 1% glycerol Yes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 3]
MOPS medium with 0.4% glucose Yes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 2]

Subunit of: MacAB-TolC macrolide efflux transport system

Synonyms: YbjYZ

Subunit composition of MacAB-TolC macrolide efflux transport system = [(TolC)3][MacB]2[MacA]6
         TolC outer membrane channel = (TolC)3 (extended summary available)
                 TolC monomer = TolC
         MacAB-TolC macrolide efflux transport system - membrane subunit = MacB (summary available)
         MacAB-TolC macrolide efflux transport system - membrane fusion protein = MacA (summary available)

Summary:
MacAB, also known as YbjYZ, probably forms a complex with outer membrane protein TolC to confer macrolide resistance via active drug efflux. The macAB genes form an operon with a single promoter and sequence analysis suggests that MacA is a peripheral membrane protein of the MFP family and MacB is a half-type ABC protein with four putative TM segments and an N-terminal nucleotide binding region with both Walker motifs and a characteristic ABC signature sequence. Expression of macAB in a drug-sensitive E. coli strain lacking the multidrug efflux transporter genes acrAB resulted in an eight-fold increased level of resistance to the macrolide erythromycin [Kobayashi01a]. Similar macAB mediated resistance was found to other macrolides with 14-and 15- membered rings, though not for 16-membered lactones. Deletion studies indicate that macAB mediated macrolide resistance is dependent on the tolC outer membrane channel protein. Fractionation studies indicate that MacA and MacB both sequester into the membrane and that MacA is released from the membrane upon treatment with urea, suggesting that MacA is a peripheral membrane protein [Yamanaka01].

Citations: [Xu11]

GO Terms:

Biological Process: GO:0046618 - drug export Inferred from experiment [Kobayashi01a]
Molecular Function: GO:0008559 - xenobiotic-transporting ATPase activity Inferred from experiment Inferred by computational analysis [Kobayashi01a, Tikhonova07]
Cellular Component: GO:0030313 - cell envelope Inferred from experiment [Kobayashi01a]


Enzymatic reaction of: transport of a macrolide antibiotic (MacAB-TolC macrolide efflux transport system)

Transport reaction diagram for transport of a macrolide antibiotic


Sequence Features

Protein sequence of MacAB-TolC macrolide efflux transport system - membrane fusion protein with features indicated

Feature Class Location Citations Comment
Transmembrane-Region 11 -> 31
[UniProt15]
UniProt: Helical.
Mutagenesis-Variant 353
[Modali11, UniProt14a]
[Modali11, UniProt14a]
[Modali11, UniProt14a]
G → S: 2-fold increase in susceptibility to macrolides.
G → A: 2-fold increase in susceptibility to macrolides. Does not affect oligomerization and ability to interact with MacB and TolC, but changes the structure of the MP region. Does not stimulate MacB ATPase activity.
G → C: 4-fold increase in susceptibility to macrolides. Does not stimulate MacB ATPase activity.
Mutagenesis-Variant 357
[Modali11, UniProt14a]
[Modali11, UniProt14a]
G → A: 2-fold increase in susceptibility to macrolides. Does not stimulate MacB ATPase activity.
G → C or S: Does not affect susceptibility to macrolides.


Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram

Transcription-unit diagram

Notes:

History:
Peter D. Karp on Wed Jan 18, 2006:
Gene left-end position adjusted based on analysis performed in the 2005 E. coli annotation update [Riley06 ].
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.


References

Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

Gerdes03: Gerdes SY, Scholle MD, Campbell JW, Balazsi G, Ravasz E, Daugherty MD, Somera AL, Kyrpides NC, Anderson I, Gelfand MS, Bhattacharya A, Kapatral V, D'Souza M, Baev MV, Grechkin Y, Mseeh F, Fonstein MY, Overbeek R, Barabasi AL, Oltvai ZN, Osterman AL (2003). "Experimental determination and system level analysis of essential genes in Escherichia coli MG1655." J Bacteriol 185(19);5673-84. PMID: 13129938

GOA01: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394

Kobayashi01a: Kobayashi N, Nishino K, Yamaguchi A (2001). "Novel macrolide-specific ABC-type efflux transporter in Escherichia coli." J Bacteriol 2001;183(19);5639-44. PMID: 11544226

Kobayashi01b: Kobayashi K, Tsukagoshi N, Aono R (2001). "Suppression of hypersensitivity of Escherichia coli acrB mutant to organic solvents by integrational activation of the acrEF operon with the IS1 or IS2 element." J Bacteriol 183(8);2646-53. PMID: 11274125

Lin09: Lin HT, Bavro VN, Barrera NP, Frankish HM, Velamakanni S, van Veen HW, Robinson CV, Borges-Walmsley MI, Walmsley AR (2009). "The MacB ABC transporter is a dimer whose ATPase activity and macrolide-binding capacity are regulated by the membrane fusion protein MacA." J Biol Chem 190(24):7876-84. PMID: 18955484

LopezCampistrou05: Lopez-Campistrous A, Semchuk P, Burke L, Palmer-Stone T, Brokx SJ, Broderick G, Bottorff D, Bolch S, Weiner JH, Ellison MJ (2005). "Localization, annotation, and comparison of the Escherichia coli K-12 proteome under two states of growth." Mol Cell Proteomics 4(8);1205-9. PMID: 15911532

Maciag11: Maciag A, Peano C, Pietrelli A, Egli T, De Bellis G, Landini P (2011). "In vitro transcription profiling of the {sigma}S subunit of bacterial RNA polymerase: re-definition of the {sigma}S regulon and identification of {sigma}S-specific promoter sequence elements." Nucleic Acids Res 39(13);5338-55. PMID: 21398637

Modali11: Modali SD, Zgurskaya HI (2011). "The periplasmic membrane proximal domain of MacA acts as a switch in stimulation of ATP hydrolysis by MacB transporter." Mol Microbiol 81(4);937-51. PMID: 21696464

Riley06: Riley M, Abe T, Arnaud MB, Berlyn MK, Blattner FR, Chaudhuri RR, Glasner JD, Horiuchi T, Keseler IM, Kosuge T, Mori H, Perna NT, Plunkett G, Rudd KE, Serres MH, Thomas GH, Thomson NR, Wishart D, Wanner BL (2006). "Escherichia coli K-12: a cooperatively developed annotation snapshot--2005." Nucleic Acids Res 34(1);1-9. PMID: 16397293

Tikhonova07: Tikhonova EB, Devroy VK, Lau SY, Zgurskaya HI (2007). "Reconstitution of the Escherichia coli macrolide transporter: the periplasmic membrane fusion protein MacA stimulates the ATPase activity of MacB." Mol Microbiol 63(3);895-910. PMID: 17214741

UniProt14a: UniProt Consortium (2014). "UniProt version 2014-08 released on 2014-08-01 00:00:00." Database.

UniProt15: UniProt Consortium (2015). "UniProt version 2015-01 released on 2015-01-16 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

Xu11: Xu Y, Song S, Moeller A, Kim N, Piao S, Sim SH, Kang M, Yu W, Cho HS, Chang I, Lee K, Ha NC (2011). "Functional implications of an intermeshing cogwheel-like interaction between TolC and MacA in the action of macrolide-specific efflux pump MacAB-TolC." J Biol Chem 286(15);13541-9. PMID: 21325274

Yamanaka01: Yamanaka N, Yamamoto Y, Kuki K (2001). "Engraftment of tonsillar mononuclear cells in human skin/SCID mouse chimera--validation of a novel xenogeneic transplantation model for autoimmune diseases." Microbiol Immunol 2001;45(7);507-14. PMID: 11529556

Yum09: Yum S, Xu Y, Piao S, Sim SH, Kim HM, Jo WS, Kim KJ, Kweon HS, Jeong MH, Jeon H, Lee K, Ha NC (2009). "Crystal structure of the periplasmic component of a tripartite macrolide-specific efflux pump." J Mol Biol 387(5);1286-97. PMID: 19254725


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Fri Sep 4, 2015, biocyc13.