Differential expression of the components of the two alkane hydroxylases from Pseudomonas aeruginosa.
Oxidation of n-alkanes in bacteria is normally initiated by an enzyme system formed by a membrane-bound alkane hydroxylase and two soluble proteins, rubredoxin and rubredoxin reductase. Pseudomonas aeruginosa strains PAO1 and RR1 contain genes encoding two alkane hydroxylases (alkB1 and alkB2), two rubredoxins (alkG1 and alkG2), and a rubredoxin reductase (alkT). We have localized the promoters for these genes and analyzed their expression under different conditions. The alkB1 and alkB2 genes were preferentially expressed at different moments of the growth phase; expression of alkB2 was highest during the early exponential phase, while alkB1 was induced at the late exponential phase, when the growth rate decreased. Both genes were induced by C(10) to C(22)/C(24) alkanes but not by their oxidation derivatives. However, the alkG1, alkG2, and alkT genes were expressed at constant levels in both the absence and presence of alkanes.
Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
Mercedes M
MM
Marín
Luis
L
Yuste
Fernando
F
Rojo
D000473:Alkanes / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002455:Cell Division / Q000235:genetics; D042926:Cytochrome P-450 CYP4A; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D011401:Promoter Regions, Genetic; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D011755:Pyrophosphatases / Q000235:genetics; D012416:Rubredoxins / Q000235:genetics / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics
D000473:Alkanes; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C080365:LasR protein, Pseudomonas aeruginosa; D012416:Rubredoxins; D012808:Sigma Factor; D015534:Trans-Activators; C069567:sigma factor KatF protein, Bacteria; C074896:rhiR protein, Rhizobium leguminosarum; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D042926:Cytochrome P-450 CYP4A; C023091:rubredoxin-NAD+ reductase; D009247:NADH, NADPH Oxidoreductases; C027627:guanosine-3',5'-bis(diphosphate) 3'-pyrophosphatase; D011755:Pyrophosphatases