Biomaterial Database

Biosynthesis of enterobacterial common antigen in Escherichia coli. In vitro synthesis of lipid-linked intermediates. 1987

K Barr, and P D Rick

An in vitro system was developed to study the biosynthesis of enterobacterial common antigen (ECA). Membranes of Escherichia coli were found to possess an enzyme activity that catalyzes the transfer of UDP-N-acetyl-acetylglucosamine-1-phosphate from UDP-N-acetyl-glucosamine (UDP-GlcNAc) to an endogenous lipid acceptor according to the reaction UDP-GlcNAc + P-lipid----GlcNAc-PP-lipid + UMP. The lipid-linked product was tentatively identified as GlcNAc-pyrophosphorylundecaprenol (lipid I) based on a comparison of its chemical and chromatographic properties with those of authentic GlcNAc-pyrophosphorylundecaprenol. The enzyme was dependent on the presence of Mg2+ for activity, and the reaction catalyzed by the enzyme was totally inhibited by the antibiotic tunicamycin in both the forward and reverse directions. Incubation of membranes with both UDP-N-acetylmannosaminuronic acid (UDP-ManNAcA) and UDP-GlcNAc resulted in the conversion of lipid I to a more polar compound, lipid II. The synthesis of lipid II was dependent on prior synthesis of lipid I. Characterization of the saccharide moiety of lipid II resulted in the identification of this compound as ManNAcA-GlcNAc-pyrophosphorylundecaprenol.

UI	MeSH Term	Description	Entries
D008055	Lipids	A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)	Lipid
D010770	Phosphotransferases	A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.	Kinases,Phosphotransferase,Phosphotransferases, ATP,Transphosphorylase,Transphosphorylases,Kinase,ATP Phosphotransferases
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D006017	Glycolipids	Any compound containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol (see GLYCERIDES), a sphingoid, a ceramide (CERAMIDES) (N-acylsphingoid) or a prenyl phosphate. (From IUPAC's webpage)	Glycolipid
D000942	Antigens, Bacterial	Substances elaborated by bacteria that have antigenic activity.	Bacterial Antigen,Bacterial Antigens,Antigen, Bacterial
D014415	Tunicamycin	An N-acetylglycosamine containing antiviral antibiotic obtained from Streptomyces lysosuperificus. It is also active against some bacteria and fungi, because it inhibits the glucosylation of proteins. Tunicamycin is used as tool in the study of microbial biosynthetic mechanisms.
D014537	Uridine Diphosphate N-Acetylglucosamine	Serves as the biological precursor of insect chitin, of muramic acid in bacterial cell walls, and of sialic acids in mammalian glycoproteins.	UDP Acetylglucosamine,UDPGNAc,Uridine Diphospho-N-Acetylglucosamine,Uridine Pyrophosphoacetylglucosamine,Uridine Diphosphate N Acetylglucosamine,Acetylglucosamine, UDP,Diphosphate N-Acetylglucosamine, Uridine,Diphospho-N-Acetylglucosamine, Uridine,N-Acetylglucosamine, Uridine Diphosphate,Pyrophosphoacetylglucosamine, Uridine,Uridine Diphospho N Acetylglucosamine
D014539	Uridine Diphosphate Sugars	Nucleotide-sugars such as uridine-diphosphate glucose or UDP-glucose.	UDP Sugars,Diphosphate Sugars, Uridine,Sugars, UDP,Sugars, Uridine Diphosphate
D017855	Transferases (Other Substituted Phosphate Groups)	A class of enzymes that transfers substituted phosphate groups. EC 2.7.8.	Phosphotransferases (Other Substituted Phosphate Groups)