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MetaCyc Polypeptide: poly-β-1,6-N-acetyl-D-glucosamine synthase - PgaC subunit

Gene: pgaC Accession Numbers: G6529 (MetaCyc), b1022, ECK1012

Synonyms: hmsR, ycdQ

Species: Escherichia coli K-12 substr. MG1655

Component of: poly-β-1,6-N-acetyl-D-glucosamine synthase (extended summary available)

Locations: inner membrane

Map Position: [1,085,744 <- 1,087,069]

Molecular Weight of Polypeptide: 50.766 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0003464 , DIP:DIP-11512N , EchoBASE:EB3623 , EcoGene:EG13863 , EcoliWiki:b1022 , Mint:MINT-1234361 , ModBase:P75905 , OU-Microarray:b1022 , PortEco:pgaC , PR:PRO_000023521 , Pride:P75905 , Protein Model Portal:P75905 , RefSeq:NP_415541 , RegulonDB:G6529 , SMR:P75905 , String:511145.b1022 , UniProt:P75905

Relationship Links: CAZy:IN-FAMILY:GT2 , InterPro:IN-FAMILY:IPR001173 , InterPro:IN-FAMILY:IPR023853 , Pfam:IN-FAMILY:PF00535

Gene-Reaction Schematic: ?

GO Terms:

Biological Process: GO:0008152 - metabolic process Inferred by computational analysis Inferred from experiment [Itoh08a, Wang04b, UniProtGOA11, GOA01]
GO:0043708 - cell adhesion involved in biofilm formation Inferred from experiment [Wang04b]
GO:0042710 - biofilm formation Inferred by computational analysis [GOA01]
Molecular Function: GO:0005515 - protein binding Inferred from experiment [Steiner13]
GO:0008375 - acetylglucosaminyltransferase activity Inferred from experiment Inferred by computational analysis [GOA01, Wang04b, Itoh08a]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11]
GO:0016757 - transferase activity, transferring glycosyl groups Inferred by computational analysis [UniProtGOA11]
Cellular Component: GO:0005886 - plasma membrane Inferred from experiment Inferred by computational analysis [UniProtGOA11a, UniProtGOA11, DiazMejia09, Daley05]
GO:0005887 - integral component of plasma membrane Inferred by computational analysis [Wang04b, Steiner13]
GO:0016020 - membrane Inferred by computational analysis [UniProtGOA11]
GO:0016021 - integral component of membrane Inferred by computational analysis [UniProtGOA11]

MultiFun Terms: metabolism biosynthesis of macromolecules (cellular constituents)

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International


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

Species: Escherichia coli K-12 substr. MG1655

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

Summary:
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 [Wang04b] 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 [Wang04b, 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 [Wang04b, 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 [Wang05c, 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 [Wang05].

PgaC has similarity to the HmsR protein encoded by the Yersinia pestis hmsHFRST gene cluster, which is involved in plague transmission [Jones99a]. E. coli PgaC functionally complements the hemin storage (Hms) phenotype of a Yersinia pestis hmsR mutant [Jones99a].

Review: [Hengge13]

Citations: [Itoh05]

Locations: inner membrane

GO Terms:

Biological Process: GO:0015774 - polysaccharide transport Inferred from experiment [Steiner13]
GO:0043708 - cell adhesion involved in biofilm formation Inferred from experiment [Wang04b]
Molecular Function: GO:0015159 - polysaccharide transmembrane transporter activity Inferred from experiment [Steiner13]
GO:0008375 - acetylglucosaminyltransferase activity Inferred by computational analysis [Wang04b]
Cellular Component: GO:0005887 - integral component of plasma membrane Inferred by computational analysis [Wang04b, Steiner13]

Credits:
Created in EcoCyc 09-Jan-2013 by Mackie A , Macquarie University
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International


Enzymatic reaction of: transport of poly-β-1,6-N-acetyl-D-glucosamine (poly-β-1,6-N-acetyl-D-glucosamine synthase)

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International


Enzymatic reaction of: poly-β-1,6-N-acetyl-D-glucosamine synthase

UDP-N-acetyl-α-D-glucosamine <=> poly-β-1,6-N-acetyl-D-glucosamine + UDP

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.

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International

Activators (Allosteric): cyclic di-3',5'-guanylate [Steiner13]

Primary Physiological Regulators of Enzyme Activity: cyclic di-3',5'-guanylate

Kinetic Parameters:

Substrate
Km (μM)
Citations
UDP-N-acetyl-α-D-glucosamine
270.0
[Steiner13]


Sequence Features

Feature Class Location Citations Comment
Transmembrane-Region 5 -> 25
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 33 -> 53
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 331 -> 351
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 363 -> 383
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 395 -> 415
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;

History:
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.


References

Cerca08: Cerca N, Jefferson KK (2008). "Effect of growth conditions on poly-N-acetylglucosamine expression and biofilm formation in Escherichia coli." FEMS Microbiol Lett 283(1);36-41. PMID: 18445167

Daley05: Daley DO, Rapp M, Granseth E, Melen K, Drew D, von Heijne G (2005). "Global topology analysis of the Escherichia coli inner membrane proteome." Science 308(5726);1321-3. PMID: 15919996

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

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

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

Hengge13: Hengge R (2013). "Novel tricks played by the second messenger c-di-GMP in bacterial biofilm formation." EMBO J 32(3);322-3. PMID: 23299943

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

Jones99a: Jones HA, Lillard JW, Perry RD (1999). "HmsT, a protein essential for expression of the haemin storage (Hms+) phenotype of Yersinia pestis." Microbiology 145 ( Pt 8);2117-28. PMID: 10463178

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

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

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 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."

Wang04b: 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

Wang05: 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

Wang05c: 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


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Sun Nov 23, 2014, biocyc13.