Mutants of Escherichia coli defective in membrane phospholipid synthesis: mapping of sn glycerol 3 phosphate acyltransferase Km mutants

plsB mutants of E. coli are sn glycerol 3 phosphate auxotrophs which owe their requirement to a K(m) defect in sn glycerol 3 phosphate acyltransferase, the first enzyme in the phospholipid biosynthetic pathway. The authors located the plsB gene at minute 69 of the E. coli genetic map, far removed from the gene defined by mutants with a temperature sensitive sn glycerol 3 phosphate acyltransferase. The plsB gene was cotransduced with the dctA locus and the transduction data indicated that the clockwise gene order is asd, plsB, dctA, xyl. plsB^- is recessive to plsB⁺ and all acyltransferase K(m) mutants tested lie very close to the plsB locus. Effective supplementation of plsB mutants was shown not to require a defective glpD gene.