Gene cloning and characterization of an aldehyde dehydrogenase from long-chain alkane-degrading Geobacillus thermoleovorans B23.
Geobacillus thermoleovorans B23 is capable of degrading long-chain alkanes at 70 degrees C. Bt-aldh, an aldehyde dehydrogenase gene in B23, was located in the upstream region of p21 whose expression level was dramatically increased when alkane degradation was started (Kato et al. 2009, BMC Microbiol 9:60). Like p21, transcription level of Bt-aldh was also increased upon alkane degradation. Bt-Aldh (497 aa, MW = 53,886) was overproduced in Escherichia coli, purified, and characterized biochemically. Bt-Aldh acted as an octamer, required NAD(+) as a coenzyme, and showed high activity against aliphatic long-chain aldehydes such as tetradecanal. The optimum condition for activity was 50-55 degrees C and pH 10.0. The activity was elevated to two- to threefold in the presence of 2 mM Ba(2+), Ca(2+), or Sr(2+), while Mg(2+) and Zn(2+) inhibited the enzyme activity. Bt-Aldh represents thermophilic aldehyde dehydrogenases responsible for degradation of long-chain alkanes.
Department of Material and Life Science, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan.
Tomohisa
T
Kato
Asuka
A
Miyanaga
Shigenori
S
Kanaya
Masaaki
M
Morikawa
D000444:Aldehyde Dehydrogenase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000473:Alkanes / Q000737:chemistry* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002413:Cations, Divalent / Q000737:chemistry; D003001:Cloning, Molecular / Q000379:methods; D004926:Escherichia coli / Q000235:genetics; D056506:Geobacillus / Q000201:enzymology* / Q000235:genetics; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity / Q000502:physiology; D014158:Transcription, Genetic / Q000502:physiology
D000473:Alkanes; D001426:Bacterial Proteins; D002413:Cations, Divalent; D008670:Metals; D011994:Recombinant Proteins; D000444:Aldehyde Dehydrogenase