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MetaCyc Enzyme: lipopolysaccharide core biosynthesis; heptosyl transferase IV; probably hexose transferase

Gene: waaU Accession Numbers: EG11423 (MetaCyc), b3623, ECK3613

Synonyms: rfaK

Species: Escherichia coli K-12 substr. MG1655

Summary:
The lipopolysaccharide of E. coli K-12 consists of two major components: the hydrophobic lipid A moiety inserted into the outer membrane and the phosphorylated core oligosaccharide [Raetz02]. E. coli K-12 does not produce O antigen to attach to the LPS core due to a defect in the rfb gene cluster which can be complemented with genes from a second, independent rfb mutant to produce an O16 type O antigen [Stevenson94]. E. coli K-12 may have two major pathways for LPS biosynthesis. One generates LPS cores suitable for O antigen attachment, and a second generates lipooligosaccharides (LOS) with modifications to the core structure which prevent O antigen attachment [Klena92].

WaaU is responsible for the attachment of HepIV to the GlcIII residue of the outer core [Heinrichs98]. A waaU mutant is unable to add O antigen when a rfb cluster is supplied on a plasmid [Klena92].

It is also suggested that WaaU may attach GlcNAc to an inner core heptose since a waaU mutant becomes sensitive to phage Br2 [Klena92].

The chromosomal waa region (formerly rfa) contains the major core-oligosaccharide assembly operons in E. coli [Raetz02][Raetz07]. The current nomenclature system was proposed originally in [Reeves96] and [Heinrichs98] and followed thereafter.

Reviews: [Raetz02, Heinrichs98, Schnaitman93]

Locations: membrane

Map Position: [3,796,262 <- 3,797,335]

Molecular Weight of Polypeptide: 41.729 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0011851 , CGSC:33791 , DIP:DIP-10672N , EchoBASE:EB1393 , EcoGene:EG11423 , EcoliWiki:b3623 , Entrez-gene:948147 , Mint:MINT-1231283 , ModBase:P27242 , OU-Microarray:b3623 , PortEco:waaU , PR:PRO_000024215 , Protein Model Portal:P27242 , RefSeq:NP_418080 , RegulonDB:EG11423 , String:511145.b3623 , UniProt:P27242

Relationship Links: CAZy:IN-FAMILY:GT9 , InterPro:IN-FAMILY:IPR002201 , Pfam:IN-FAMILY:PF01075

Gene-Reaction Schematic: ?

GO Terms:

Biological Process: GO:0009244 - lipopolysaccharide core region biosynthetic process Inferred from experiment Inferred by computational analysis [UniProtGOA12, Klena92]
GO:0008152 - metabolic process Inferred by computational analysis [GOA01]
GO:0009103 - lipopolysaccharide biosynthetic process Inferred by computational analysis [UniProtGOA11]
Molecular Function: GO:0016757 - transferase activity, transferring glycosyl groups Inferred from experiment Inferred by computational analysis [UniProtGOA11, GOA01, Klena92]
GO:0008917 - lipopolysaccharide N-acetylglucosaminyltransferase activity Inferred by computational analysis [GOA01a]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11]
Cellular Component: GO:0016020 - membrane Inferred by computational analysis [UniProtGOA11a, UniProtGOA11]

MultiFun Terms: cell structure surface antigens (ECA, O antigen of LPS)
metabolism biosynthesis of macromolecules (cellular constituents) lipopolysaccharide core region

Credits:
Reviewed in EcoCyc 22-Feb-2010 by Sarker M
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International


Enzymatic reaction of: Lipopolysaccharide 1,2-N-acetylglucosaminetransferase (lipopolysaccharide core biosynthesis; heptosyl transferase IV; probably hexose transferase)

EC Number: 2.4.1.56

a lipopolysaccharide + UDP-N-acetyl-α-D-glucosamine <=> a N-acetyl-α-D-glucosaminyl-lipopolysaccharide + UDP

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

Reversibility of this reaction is unspecified.

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


Enzymatic reaction of: Lipid A-core heptosyl transferase (lipopolysaccharide core biosynthesis; heptosyl transferase IV; probably hexose transferase)

EC Number: 2.4.-.-

galactosyl-(glucosyl)3-(heptosyl)3-Kdo2-lipid A-bisphosphate + ADP-L-glycero-β-D-manno-heptose <=> lipid A-core + ADP + H+

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.

The reaction is favored in the direction shown.

In Pathways: superpathway of lipopolysaccharide biosynthesis , Lipid A-core biosynthesis

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


Sequence Features

Feature Class Location Citations Comment
Sequence-Conflict 293
[Klena92a, UniProt10a]
Alternate sequence: M; UniProt: (in Ref. 1; AAA24523);

History:
10/20/97 Gene b3623 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11423; confirmed by SwissProt match.


References

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

GOA01a: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

Heinrichs98: Heinrichs DE, Yethon JA, Whitfield C (1998). "Molecular basis for structural diversity in the core regions of the lipopolysaccharides of Escherichia coli and Salmonella enterica." Mol Microbiol 30(2);221-32. PMID: 9791168

Klena92: Klena JD, Ashford RS, Schnaitman CA (1992). "Role of Escherichia coli K-12 rfa genes and the rfp gene of Shigella dysenteriae 1 in generation of lipopolysaccharide core heterogeneity and attachment of O antigen." J Bacteriol 174(22);7297-307. PMID: 1385388

Klena92a: Klena JD, Pradel E, Schnaitman CA (1992). "Comparison of lipopolysaccharide biosynthesis genes rfaK, rfaL, rfaY, and rfaZ of Escherichia coli K-12 and Salmonella typhimurium." J Bacteriol 174(14);4746-52. PMID: 1624462

Raetz02: Raetz CR, Whitfield C (2002). "Lipopolysaccharide endotoxins." Annu Rev Biochem 71;635-700. PMID: 12045108

Raetz07: Raetz CR, Reynolds CM, Trent MS, Bishop RE (2007). "Lipid A modification systems in gram-negative bacteria." Annu Rev Biochem 76;295-329. PMID: 17362200

Reeves96: Reeves PR, Hobbs M, Valvano MA, Skurnik M, Whitfield C, Coplin D, Kido N, Klena J, Maskell D, Raetz CR, Rick PD (1996). "Bacterial polysaccharide synthesis and gene nomenclature." Trends Microbiol 4(12);495-503. PMID: 9004408

Schnaitman93: Schnaitman CA, Klena JD (1993). "Genetics of lipopolysaccharide biosynthesis in enteric bacteria." Microbiol Rev 57(3);655-82. PMID: 7504166

Stevenson94: Stevenson G, Neal B, Liu D, Hobbs M, Packer NH, Batley M, Redmond JW, Lindquist L, Reeves P (1994). "Structure of the O antigen of Escherichia coli K-12 and the sequence of its rfb gene cluster." J Bacteriol 1994;176(13);4144-56. PMID: 7517391

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-11 released on 2010-11-02 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."

UniProtGOA12: UniProt-GOA (2012). "Gene Ontology annotation based on UniPathway vocabulary mapping."


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 Thu Dec 18, 2014, biocyc14.