Dh. Li et Kj. Stevenson, PURIFICATION AND SEQUENCE-ANALYSIS OF A NOVEL NADP(H)DEPENDENT TYPE-III ALCOHOL-DEHYDROGENASE FROM THERMOCOCCUS STRAIN AN1, Journal of bacteriology, 179(13), 1997, pp. 4433-4437
An NADP(H)-dependent alcohol dehydrogenase was isolated from the hyper
thermophilic archaeon Thermococcus strain AN1. This enzyme is a homote
tramer with a subunit molecular weight of 46,700. The enzyme oxidizes
a series of primary linear alcohols but not methanol. The pH and tempe
rature optima with ethanol as the substrate are 6.8 to 7.0 and 85 degr
ees C, respectively. The enzyme readily reduced acetaldehyde,vith NADP
H as the cofactor. The gene encoding this enzyme has been cloned and s
equenced. An open reading Game of 1,218 bp, starting with ATG and endi
ng with TGA, was identified and corresponded to 406 amino acids. Seque
nce comparisons show that this Thermococcus strain AN1 enzyme has sign
ificant homologies,vith enzymes from the newly defined type III alcoho
l dehydrogenase family. Thermococcus strain AN1 alcohol dehydrogenase
is the first archaeal enzyme belonging to this family.