Mutations affecting the synthesis of NADP-dependent glutamate dehydrogenase in Pseudomonas aeruginosa.
NADP-dependent glutamate dehydrogenase (NADP-GDH) was purified to homogeneity from Pseudomonas aeruginosa strain 8602 (PAC 1). The Mr determined by Sephadex gel filtration was 280,000; the subunit Mr determined by SDS-PAGE was 45,000. Mutant strains lacking NADP-GDH and glutamate synthase (Gdh-Glt-) required glutamate for growth. Transductants that lacked only NADP-GDH were indistinguishable from the wild-type strain in growth properties. It was concluded that NADP-GDH is not essential for growth of the wild-type organism and that glutamate formation via NAD-dependent glutamate dehydrogenase does not occur to a significant extent. A mutant strain, 39, producing high NADP-GDH activity, synthesized normal NADP-GDH and had the same intracellular glutamate concentrations as its parent. The mutation responsible for the synthesis of high levels of NADP-GDH was shown, by transduction, to be closely linked to the NADP-GDH structural gene (gdhA).
Joannou
C L
CL
Department of Biochemistry, King's College London, UK.
Brown
P R
PR
Tata
R
R
D008040:Genetic Linkage; D005969:Glutamate Dehydrogenase / Q000096:biosynthesis* / Q000302:isolation & purification; D018086:Glutamate Dehydrogenase (NADP+); D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000254:growth & development; D014161:Transduction, Genetic
D005969:Glutamate Dehydrogenase; D018086:Glutamate Dehydrogenase (NADP+)