The genes rubA and rubB for alkane degradation in Acinetobacter sp. strain ADP1 are in an operon with estB, encoding an esterase, and oxyR.
Alkanes are oxidized in Acinetobacter sp. strain ADP1 by a three-component alkane monooxygenase, composed of alkane hydroxylase, rubredoxin, and rubredoxin reductase. rubA and rubB encode rubredoxin and a NAD(P)H-dependent rubredoxin reductase. We demonstrate here that single base pair substitutions in rubA or rubB lead to defects in alkane degradation, showing that both genes are essential for alkane utilization. Differences in the degradation capacity for hexadecane and dodecane in these mutants are discussed. Two genes, estB and oxyR, are located downstream of rubB, but are not necessary for alkane degradation. estB encodes a functional esterase. oxyR encodes a LysR-type transcriptional regulator, conferring resistance to hydrogen peroxide. rubA, rubB, estB, and oxyR constitute an operon, which is constitutively transcribed from a sigma70 promoter, and an estB-oxyR containing message is also transcribed from an internal promoter.
Lehrstuhl für Mikrobiologie, Institut für Mikrobiologie, Biochemie und Genetik der Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
W
W
Geissdörfer
R G
RG
Kok
A
A
Ratajczak
K J
KJ
Hellingwerf
W
W
Hillen
D000150:Acinetobacter / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D000473:Alkanes / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D001673:Biodegradation, Environmental; D004269:DNA, Bacterial / Q000032:analysis; D004268:DNA-Binding Proteins; D004950:Esterases / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D009876:Operon; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012416:Rubredoxins / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D000473:Alkanes; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D012416:Rubredoxins; D014157:Transcription Factors; D006861:Hydrogen Peroxide; C023091:rubredoxin-NAD+ reductase; D009247:NADH, NADPH Oxidoreductases; D004950:Esterases