Biomaterial Database

Pathways for the incorporation of exogenous fatty acids into phosphatidylethanolamine in Escherichia coli. 1985

C O Rock, and S Jackowski

Two distinct pathways for the incorporation of exogenous fatty acids into phospholipids were identified in Escherichia coli. The predominant route originates with the activation of fatty acids by acyl-CoA synthetase followed by the distribution of the acyl moieties into all phospholipid classes via the sn-glycerol-3-phosphate acyltransferase reaction. This pathway was blocked in mutants (fadD) lacking acyl-CoA synthetase activity. In fadD strains, exogenous fatty acids were introduced exclusively into the 1-position of phosphatidylethanolamine. This secondary route is related to 1-position fatty acid turnover in phosphatidylethanolamine and proceeds via the acyl-acyl carrier protein synthetase/2-acylglycerophosphoethanolamine acyltransferase system. The turnover pathway exhibited a preference for saturated fatty acids, whereas the acyl-CoA synthetase-dependent pathway was less discriminating. Both pathways were inhibited in mutants (fadL) lacking the fatty acid permease, demonstrating that the fadL gene product translocates exogenous fatty acids to an intracellular pool accessible to both synthetases. These data demonstrate that acyl-CoA synthetase is not required for fatty acid transport in E. coli and that the metabolism of exogenous fatty acids is segregated from the metabolism of acyl-acyl carrier proteins derived from fatty acid biosynthesis.

UI	MeSH Term	Description	Entries
D008025	Ligases	A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor. (Dorland, 28th ed) EC 6.	Ligase,Synthetases,Synthetase
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009829	Oleic Acids	A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.	Octadecenoic Acids,Acids, Octadecenoic,Acids, Oleic
D010169	Palmitic Acids	A group of 16-carbon fatty acids that contain no double bonds.	Acids, Palmitic
D010714	Phosphatidylethanolamines	Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to an ethanolamine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and ethanolamine and 2 moles of fatty acids.	Cephalin,Cephalins,Ethanolamine Phosphoglyceride,Ethanolamine Phosphoglycerides,Ethanolamineglycerophospholipids,Phosphoglyceride, Ethanolamine,Phosphoglycerides, Ethanolamine
D003066	Coenzyme A Ligases	Enzymes that catalyze the formation of acyl-CoA derivatives. EC 6.2.1.	Acyl CoA Synthetase,Acyl CoA Synthetases,Acyl Coenzyme A Synthetase,Acyl Coenzyme A Synthetases,Coenzyme A Ligase,Coenzyme A Synthetase,Coenzyme A Synthetases,Acid-Thiol Ligases,Co A Ligases,A Ligase, Coenzyme,A Synthetase, Coenzyme,Acid Thiol Ligases,CoA Synthetase, Acyl,CoA Synthetases, Acyl,Ligase, Coenzyme A,Ligases, Acid-Thiol,Ligases, Co A,Ligases, Coenzyme A,Synthetase, Acyl CoA,Synthetase, Coenzyme A,Synthetases, Acyl CoA,Synthetases, Coenzyme A
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
D005227	Fatty Acids	Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)	Aliphatic Acid,Esterified Fatty Acid,Fatty Acid,Fatty Acids, Esterified,Fatty Acids, Saturated,Saturated Fatty Acid,Aliphatic Acids,Acid, Aliphatic,Acid, Esterified Fatty,Acid, Saturated Fatty,Esterified Fatty Acids,Fatty Acid, Esterified,Fatty Acid, Saturated,Saturated Fatty Acids
D005992	Glycerol-3-Phosphate O-Acyltransferase	An enzyme that transfers acyl groups from acyl-CoA to glycerol-3-phosphate to form monoglyceride phosphates. It acts only with CoA derivatives of fatty acids of chain length above C-10. Also forms diglyceride phosphates. EC 2.3.1.15.	Glycerolphosphate Acyltransferase,Stearyl-CoA Glycerophosphate Transstearylase,Acyl-CoA Sn-Glycerol-3-Phosphate-O-Acyltransferase,Glycerophosphate Acyltransferase,Acyl CoA Sn Glycerol 3 Phosphate O Acyltransferase,Acyltransferase, Glycerolphosphate,Acyltransferase, Glycerophosphate,Glycerol 3 Phosphate O Acyltransferase,Glycerophosphate Transstearylase, Stearyl-CoA,O-Acyltransferase, Glycerol-3-Phosphate,Sn-Glycerol-3-Phosphate-O-Acyltransferase, Acyl-CoA,Stearyl CoA Glycerophosphate Transstearylase,Transstearylase, Stearyl-CoA Glycerophosphate
D000217	Acyltransferases	Enzymes from the transferase class that catalyze the transfer of acyl groups from donor to acceptor, forming either esters or amides. (From Enzyme Nomenclature 1992) EC 2.3.	Acyltransferase