D-Alanine dehydrogenase. Its role in the utilisation of alanine isomers as growth substrates by Pseudomonas aeruginosa PA01.
Pseudomonas aeruginosa PA01 was found to utilise both the D- and L-isomers of alpha-alanine and also beta-alanine as sole sources of carbon and energy for growth. Enzymological studies of wild-type cultures and comparison with mutants deficient in growth upon one or more isomers of alanine led to the following conclusions: (i) utilisation of D-alanine involved its direct oxidation by an inducible, membrane-bound, cytochrome-linked dehydrogenase; (ii) utilisation of L-alanine required its conversion to the directly oxidisable D-form by a soluble racemase; (iii) utilisation of beta-alanine, like L-alanine, involves both the racemase and D-alanine dehydrogenase enzymes, but in addition must involve other enzymes the identity of which is still speculative; (iv) P. aeruginosa, like Escherichia coli, appears to take up D-alanine and L-alanine by means of two specific permeases.
D000409:Alanine / Q000378:metabolism*; D000411:Alanine Racemase / Q000378:metabolism; D003580:Cytochromes / Q000032:analysis; D003605:D-Amino-Acid Oxidase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D026901:Membrane Transport Proteins / Q000378:metabolism; D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000254:growth & development; D013237:Stereoisomerism; D013347:Subcellular Fractions / Q000201:enzymology
D003580:Cytochromes; D026901:Membrane Transport Proteins; D003605:D-Amino-Acid Oxidase; D000411:Alanine Racemase; D000409:Alanine