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Incorporation of extracellular fatty acids by a fatty acid kinase‐dependent pathway in S taphylococcus aureus
Author(s) -
Parsons Joshua B.,
Frank Matthew W.,
Jackson Pamela,
Subramanian Chitra,
Rock Charles O.
Publication year - 2014
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12556
Subject(s) - biochemistry , phosphatidic acid , fatty acid , biology , acyltransferase , fatty acid synthesis , acylation , extracellular , acyl carrier protein , acyl group , free fatty acid receptor , kinase , acyl coa , phospholipid , biosynthesis , polyunsaturated fatty acid , enzyme , chemistry , alkyl , organic chemistry , membrane , catalysis
Summary Acyl‐ CoA and acyl‐acyl carrier protein ( ACP ) synthetases activate exogenous fatty acids for incorporation into phospholipids in G ram‐negative bacteria. However, Gram‐positive bacteria utilize an acyltransferase pathway for the biogenesis of phosphatidic acid that begins with the acylation of sn ‐glycerol‐3‐phosphate by PlsY using an acyl‐phosphate (acyl‐ PO 4 ) intermediate. PlsX generates acyl‐ PO 4 from the acyl‐ ACP end‐products of fatty acid synthesis. The plsX gene of S taphylococcus aureus was inactivated and the resulting strain was both a fatty acid auxotroph and required de novo fatty acid synthesis for growth. Exogenous fatty acids were only incorporated into the 1‐position and endogenous acyl groups were channeled into the 2‐position of the phospholipids in strain PDJ39 (Δ plsX ). Extracellular fatty acids were not elongated. Removal of the exogenous fatty acid supplement led to the rapid accumulation of intracellular acyl‐ ACP and the abrupt cessation of fatty acid synthesis. Extracts from the Δ plsX strain exhibited an ATP ‐dependent fatty acid kinase activity, and the acyl‐ PO 4 was converted to acyl‐ ACP when purified PlsX is added. These data reveal the existence of a novel fatty acid kinase pathway for the incorporation of exogenous fatty acids into S . aureus phospholipids.