|Gene:||pgaD||Accession Numbers: G6528 (EcoCyc), b1021, ECK1011|
Synonyms: hmsS, ycdP
Component of: poly-β-1,6-N-acetyl-D-glucosamine synthase (extended summary available)
Locations: inner membrane
|Map Position: [1,085,329 <- 1,085,742] (23.39 centisomes)||Length: 414 bp / 137 aa|
Molecular Weight of Polypeptide: 16.082 kD (from nucleotide sequence)
Unification Links: ASAP:ABE-0003460 , DIP:DIP-48114N , EchoBASE:EB3622 , EcoGene:EG13862 , EcoliWiki:b1021 , OU-Microarray:b1021 , PortEco:pgaD , PR:PRO_000023522 , Protein Model Portal:P69432 , RefSeq:NP_415540 , RegulonDB:G6528 , String:511145.b1021 , UniProt:P69432
|Biological Process:||GO:0043708 - cell adhesion involved in biofilm formation
GO:0042710 - biofilm formation [GOA01a]
|Molecular Function:||GO:0005515 - protein binding [Rajagopala14, Steiner13, Butland05]|
|Cellular Component:||GO:0005886 - plasma membrane
[UniProtGOA11, UniProtGOA11a, DiazMejia09, Daley05]
GO:0005887 - integral component of plasma membrane [Wang04a, Steiner13]
GO:0016020 - membrane [UniProtGOA11a]
GO:0016021 - integral component of membrane [UniProtGOA11a]
|MultiFun Terms:||metabolism → biosynthesis of macromolecules (cellular constituents)|
|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: poly-β-1,6-N-acetyl-D-glucosamine synthase
Synonyms: UDP-N-acetyl-D-glucosamine β-1,6-N-acetyl-D-glucosaminyl transferase, PgaCD
Subunit composition of
poly-β-1,6-N-acetyl-D-glucosamine synthase = [PgaD][PgaC]
poly-β-1,6-N-acetyl-D-glucosamine synthase - PgaD subunit = PgaD
poly-β-1,6-N-acetyl-D-glucosamine synthase - PgaC subunit = PgaC
PgaCD is a β-glycosyltransferase which polymerises poly-N-acetyl glucosamine (PGA), an adhesin essential in biofilm formation, from an activated UDP-N-acetyl-D-glucosamine (UDP-GlcNAc) precursor [Wang04a] and transports it across the inner membrane for deacetylation and export by the OM proteins PgaB and PgaA.
PgaC and PgaD form a stable complex [Steiner13]. The second messenger cyclic di-3',5'-guanylate (c-di-GMP) stimulates PgaC-PgaD interaction and complex stability. c-di-GMP binds concurrently to PgaC-PgaD in vitro and no specific binding is observed in membranes containing only PgaC or PgaD. The binding of c-di-GMP to PgaCD increases in the presence of UDP-GlcNAc [Steiner13]. PgaD levels decrease in a strain lacking PgaC but are restored in a c-di-GMP manner when pgaC is expressed from a plasmid. PgaD levels decrease in a strain lacking diguanylate cyclase. c-di-GMP binds to PgaCD with high affinity, increasing the enzyme's velocity but not its affinity for substrate. c-di-GMP is an allosteric activator and stimulates the glycosyltransferase activity of PgaCD approximately 20-fold in vitro [Steiner13].
pgaC and pgaD mutants show reduced biofilm formation and do not accumulate PGA in a crsA background compared to wild-type [Wang04a, Itoh08a]. PgaC contains 4 predicted trans-membrane domains plus 2 membrane-associated domains; PgaD contains 2 predicted trans-membrane domains. PgaC also contains 2 catalytic domains predicted to be in the cytoplasm. The N and C-termini of both proteins are predicted to be in the cytoplasm [Wang04a, Steiner13].
Expression of pgaABCD is higher at 37° C than at 21° C and is highest during stationary phase [Cerca08]. Expression also increased in response to one-percent NaCl or ethanol [Cerca08]. Expression increased in response to glucose, ethanol, NaCl, and MnCl2 in a clinical isolate, and dramatically increased upon deletion or mutation of csrA in this strain [Cerca08, Mercante06]. CsrA inhibits translation of pgaABCD mRNA by binding to six sites within the pgaABCD leader [Wang05b, Mercante06]. NaCl and alkaline pH induction are dependent upon nhaR as deletion of this gene prevented induction [Goller06, Cerca08]. Expression of pgaC increased in response to luxS deletion at OD 2.4 in LB [Wang05c].
PgaC has similarity to the HmsR protein encoded by the Yersinia pestis hmsHFRST gene cluster, which is involved in plague transmission [Jones99]. E. coli PgaC functionally complements the hemin storage (Hms) phenotype of a Yersinia pestis hmsR mutant [Jones99].
Locations: inner membrane
|Biological Process:||GO:0015774 - polysaccharide transport
GO:0043708 - cell adhesion involved in biofilm formation [Wang04a]
|Molecular Function:||GO:0015159 - polysaccharide transmembrane transporter activity
GO:0008375 - acetylglucosaminyltransferase activity [Wang04a]
|Cellular Component:||GO:0005887 - integral component of plasma membrane [Wang04a, Steiner13]|
Enzymatic reaction of: transport of poly-β-1,6-N-acetyl-D-glucosamine (poly-β-1,6-N-acetyl-D-glucosamine synthase)
Enzymatic reaction of: poly-β-1,6-N-acetyl-D-glucosamine synthase
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
Reversibility of this reaction is unspecified.
Primary Physiological Regulators of Enzyme Activity: cyclic di-3',5'-guanylate
|Transmembrane-Region||24 -> 44|
|Transmembrane-Region||54 -> 74|
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.
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
Butland05: Butland G, Peregrin-Alvarez JM, Li J, Yang W, Yang X, Canadien V, Starostine A, Richards D, Beattie B, Krogan N, Davey M, Parkinson J, Greenblatt J, Emili A (2005). "Interaction network containing conserved and essential protein complexes in Escherichia coli." Nature 433(7025);531-7. PMID: 15690043
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
Goller06: Goller C, Wang X, Itoh Y, Romeo T (2006). "The cation-responsive protein NhaR of Escherichia coli activates pgaABCD transcription, required for production of the biofilm adhesin poly-beta-1,6-N-acetyl-D-glucosamine." J Bacteriol 188(23);8022-32. PMID: 16997959
Itoh05: Itoh Y, Wang X, Hinnebusch BJ, Preston JF, Romeo T (2005). "Depolymerization of beta-1,6-N-acetyl-D-glucosamine disrupts the integrity of diverse bacterial biofilms." J Bacteriol 187(1);382-7. PMID: 15601723
Itoh08a: Itoh Y, Rice JD, Goller C, Pannuri A, Taylor J, Meisner J, Beveridge TJ, Preston JF, Romeo T (2008). "Roles of pgaABCD genes in synthesis, modification, and export of the Escherichia coli biofilm adhesin poly-beta-1,6-N-acetyl-D-glucosamine." J Bacteriol 190(10);3670-80. PMID: 18359807
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
Mercante06: Mercante J, Suzuki K, Cheng X, Babitzke P, Romeo T (2006). "Comprehensive alanine-scanning mutagenesis of Escherichia coli CsrA defines two subdomains of critical functional importance." J Biol Chem 281(42);31832-42. PMID: 16923806
Rajagopala14: Rajagopala SV, Sikorski P, Kumar A, Mosca R, Vlasblom J, Arnold R, Franca-Koh J, Pakala SB, Phanse S, Ceol A, Hauser R, Siszler G, Wuchty S, Emili A, Babu M, Aloy P, Pieper R, Uetz P (2014). "The binary protein-protein interaction landscape of Escherichia coli." Nat Biotechnol 32(3);285-90. PMID: 24561554
Steiner13: Steiner S, Lori C, Boehm A, Jenal U (2013). "Allosteric activation of exopolysaccharide synthesis through cyclic di-GMP-stimulated protein-protein interaction." EMBO J 32(3);354-68. PMID: 23202856
Wang04a: Wang X, Preston JF, Romeo T (2004). "The pgaABCD locus of Escherichia coli promotes the synthesis of a polysaccharide adhesin required for biofilm formation." J Bacteriol 186(9);2724-34. PMID: 15090514
Wang05b: Wang X, Dubey AK, Suzuki K, Baker CS, Babitzke P, Romeo T (2005). "CsrA post-transcriptionally represses pgaABCD, responsible for synthesis of a biofilm polysaccharide adhesin of Escherichia coli." Mol Microbiol 56(6);1648-63. PMID: 15916613
Wang05c: Wang L, Li J, March JC, Valdes JJ, Bentley WE (2005). "luxS-dependent gene regulation in Escherichia coli K-12 revealed by genomic expression profiling." J Bacteriol 187(24);8350-60. PMID: 16321939
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