title: Biosynthesis pathway of ADP-L-glycero-beta-D-manno-heptose in Escherichia coli.
abstract: The steps involved in the biosynthesis of the ADP-L-glycero-beta-D-manno-heptose (ADP-L-beta-D-heptose) precursor of the inner core lipopolysaccharide (LPS) have not been completely elucidated. In this work, we have purified the enzymes involved in catalyzing the intermediate steps leading to the synthesis of ADP-D-beta-D-heptose and have biochemically characterized the reaction products by high-performance anion-exchange chromatography. We have also constructed a deletion in a novel gene, gmhB (formerly yaeD), which results in the formation of an altered LPS core. This mutation confirms that the GmhB protein is required for the formation of ADP-D-beta-D-heptose. Our results demonstrate that the synthesis of ADP-D-beta-D-heptose in Escherichia coli requires three proteins, GmhA (sedoheptulose 7-phosphate isomerase), HldE (bifunctional D-beta-D-heptose 7-phosphate kinase/D-beta-D-heptose 1-phosphate adenylyltransferase), and GmhB (D,D-heptose 1,7-bisphosphate phosphatase), as well as ATP and the ketose phosphate precursor sedoheptulose 7-phosphate. A previously characterized epimerase, formerly named WaaD (RfaD) and now renamed HldD, completes the pathway to form the ADP-L-beta-D-heptose precursor utilized in the assembly of inner core LPS.
authors.affiliation: Zentrum für Ultrastrukturforschung und Ludwig Boltzmann-Institut für Molekulare Nanotechnologie, A-1180 Vienna, Austria.
authors.forename: Bernd
authors.initials: B
authors.lastname: Kneidinger
authors.forename: Cristina
authors.initials: C
authors.lastname: Marolda
authors.forename: Michael
authors.initials: M
authors.lastname: Graninger
authors.forename: Alla
authors.initials: A
authors.lastname: Zamyatina
authors.forename: Fiona
authors.initials: F
authors.lastname: McArthur
authors.forename: Paul
authors.initials: P
authors.lastname: Kosma
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valvano
authors.forename: Paul
authors.initials: P
authors.lastname: Messner
mesh_terms: D000247:Adenosine Diphosphate Sugars / Q000096:biosynthesis*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins; D015870:Gene Expression; D007535:Isomerases / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides; D009097:Multienzyme Complexes / Q000145:classification / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000145:classification / Q000378:metabolism*; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000145:classification / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D019998:Racemases and Epimerases / Q000145:classification / Q000378:metabolism*; D009626:Terminology as Topic
chemical_list: D000247:Adenosine Diphosphate Sugars; D029968:Escherichia coli Proteins; D008070:Lipopolysaccharides; D009097:Multienzyme Complexes; C031557:adenosine 5'-diphosphate-glycero-mannoheptose; D011494:Protein Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D009713:Nucleotidyltransferases; C445302:D,D heptose 7-phosphate kinase-D,D-heptose 1-phosphate adenylyltransferase, E coli; C445300:D,D-heptose 1,7-bisphosphate phosphatase, E coli; D010749:Phosphoprotein Phosphatases; D010744:Phosphoric Monoester Hydrolases; D007535:Isomerases; D019998:Racemases and Epimerases; C445301:GmhA protein, E coli