Gene structure and regulation of alkane monooxygenases in propane-utilizing Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7.
Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7 were isolated from soil samples as propane-utilizing bacteria and were found to be able to utilize various gaseous and liquid n-alkanes as carbon and energy sources. One gene cluster, M-prmABCD, and two gene clusters, P-prm1ABCD and P-prm2ABCD, were cloned from the genomes of Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7, respectively. These gene clusters are homologous to the gene cluster encoding the multicomponent propane monooxygenase (prmABCD) of Gordonia sp. TY-5. The expression of prm gene clusters in Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7 was shown to be induced by gaseous n-alkanes (C2-C4) except methane, suggesting that the products of these genes are involved in gaseous n-alkane oxidation. Homologous genes for an alkane hydroxylase system (alk system) involved in liquid n-alkane oxidation were also cloned from the genomic DNA of Mycobacterium sp. TY-6. The alk gene cluster was transcribed in response to liquid n-alkanes (C11-C15). These results indicate that Mycobacterium sp. TY-6 has two distinct gene clusters for multicomponent monooxygenases involved in alkane oxidation. Whole-cell reactions revealed that propane is oxidized to 1-propanol through terminal oxidation in Mycobacterium sp. TY-6 and that propane is oxidized to 1-propanol and 2-propanol through both terminal and subterminal oxidations in Pseudonocardia sp. TY-7. This study reveals the diversity of propane metabolism present in microorganisms.
Kotani
Tetsuya
T
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake, Kyoto, Japan.
Kawashima
Yui
Y
Yurimoto
Hiroya
H
Kato
Nobuo
N
Sakai
Yasuyoshi
Y
D000192:Actinomycetales / Q000201:enzymology / Q000235:genetics*; D000473:Alkanes / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D016680:Genome, Bacterial / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D009161:Mycobacterium / Q000201:enzymology / Q000235:genetics*; D010084:Oxidation-Reduction; D012988:Soil Microbiology
D000473:Alkanes; D001426:Bacterial Proteins; D006899:Mixed Function Oxygenases