Characterization of the physiological substrate for lipopolysaccharide heptosyltransferases I and II.
L-Glycero-D-manno-heptopyranose is a characteristic compound of many lipopolysaccharide (LPS) core structures of Gram-negative bacteria. In Escherichia coli two heptosyltransferases, namely WaaC and WaaF, are known to transfer L-glycero-D-manno-heptopyranose to Re-LPS and Rd(2)-LPS, respectively. It had been proposed that both reactions involve ADPL-glycero-D-manno-heptose as a sugar donor; however, the structure of this nucleotide sugar had never been completely elucidated. In the present study, ADPL-glycero-D-manno-heptose was isolated from a heptosyltransferase-deficient E. coli mutant, and its structure was determined by nuclear magnetic resonance spectroscopy and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry as ADPL-glycero-beta-D-manno-heptopyranose. This compound represented the sole constituent of the bacterial extract that was accepted as a sugar donor by heptosyltransferases I and II in vitro.
Gronow
S
S
Medical and Biochemical Microbiology, Research Center Borstel, Germany.
Oertelt
C
C
Ervelä
E
E
Zamyatina
A
A
Kosma
P
P
Skurnik
M
M
Holst
O
O
D000247:Adenosine Diphosphate Sugars / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D016695:Glycosyltransferases / Q000378:metabolism*; D006539:Heptoses / Q000737:chemistry / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity / Q000502:physiology
D000247:Adenosine Diphosphate Sugars; D006539:Heptoses; C062615:glycero-alpha-manno-heptopyranose; C026312:glycero-manno-heptose; D016695:Glycosyltransferases; C086735:heptosyltransferase; C080934:lipooligosaccharide 1,5-heptosyltransferase