Expression of Vibrio harveyi acyl-ACP synthetase allows efficient entry of exogenous fatty acids into the Escherichia coli fatty acid and lipid A synthetic pathways.
Although the Escherichia coli fatty acid synthesis (FAS) pathway is the best studied type II fatty acid synthesis system, a major experimental limitation has been the inability to feed intermediates into the pathway in vivo because exogenously supplied free fatty acids are not efficiently converted to the acyl-acyl carrier protein (ACP) thioesters required by the pathway. We report that expression of Vibrio harveyi acyl-ACP synthetase (AasS), a soluble cytosolic enzyme that ligates free fatty acids to ACP to form acyl-ACPs, allows exogenous fatty acids to enter the E. coli fatty acid synthesis pathway. The free fatty acids are incorporated intact and can be elongated or directly incorporated into complex lipids by acyltransferases specific for acyl-ACPs. Moreover, expression of AasS strains and supplementation with the appropriate fatty acid restored growth to E. coli mutant strains that lack essential fatty acid synthesis enzymes. Thus, this strategy provides a new tool for circumventing the loss of enzymes essential for FAS function.
Jiang
Yanfang
Y
Department of Microbiology, University of Illinois, Urbana, Illinois 61801, USA.
Morgan-Kiss
Rachael M
RM
Campbell
John W
JW
Chan
Chi Ho
CH
Cronan
John E
JE
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D019730:Carbon-Sulfur Ligases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis*; D008050:Lipid A / Q000096:biosynthesis*; D013379:Substrate Specificity; D014733:Vibrio / Q000201:enzymology* / Q000378:metabolism
D005227:Fatty Acids; D008050:Lipid A; D000217:Acyltransferases; C034919:acyl protein synthetase; D019730:Carbon-Sulfur Ligases; C018749:long-chain-fatty-acid-(acyl-carrier-protein) ligase