Mutants of Escherichia coli Defective in Membrane Phospholipid Synthesis: Mapping of the Structural Gene for l -Glycerol 3-Phosphate Dehydrogenase

Abstract

The structural gene for the biosynthetic l -glycerol 3-phosphate dehydrogenase has been mapped at min 71.5 on the Escherichia coli chromosome. This gene ( gpsA ) is co-transduced with the xyl, mtl , and pyrE loci. Three-factor conjugational crosses and the transduction data indicate that the order of loci in this region of the chromosone is mtl, gltE, gpsA, gadR, gadS, pyrE . Study of a temperature-sensitive gpsA mutant possessing a dehydrogenase of increased thermolability indicated that gpsA is the structural gene for the dehydrogenase. All dehydrogenase-deficient strains tested were mapped very close to the gpsA locus. Attempts at genetic complementation analysis were unsuccessful.