Identification of lactaldehyde dehydrogenase in Methanocaldococcus jannaschii and its involvement in production of lactate for F420 biosynthesis.
One of the early steps in the biosynthesis of coenzyme F(420) in Methanocaldococcus jannaschii requires generation of 2-phospho-L-lactate, which is formed by the phosphorylation of L-lactate. Preliminary studies had shown that L-lactate in M. jannaschii is not derived from pyruvate, and thus an alternate pathway(s) for its formation was examined. Here we report that L-lactate is formed by the NAD(+)-dependent oxidation of l-lactaldehyde by the MJ1411 gene product. The lactaldehyde, in turn, was found to be generated either by the NAD(P)H reduction of methylglyoxal or by the aldol cleavage of fuculose-1-phosphate by fuculose-1-phosphate aldolase, the MJ1418 gene product.
Department of Biochemistry (0308), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Laura L
LL
Grochowski
Huimin
H
Xu
Robert H
RH
White
D000445:Aldehyde Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D000447:Aldehydes / Q000378:metabolism; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005634:Fructose-Bisphosphate Aldolase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006600:Hexosephosphates / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism*; D017015:Methanococcales / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D011765:Pyruvaldehyde / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012256:Riboflavin / Q000031:analogs & derivatives* / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid
D000447:Aldehydes; D019843:Archaeal Proteins; D006600:Hexosephosphates; D011994:Recombinant Proteins; C048089:fuculose 1-phosphate; D019344:Lactic Acid; C014634:lactaldehyde; C015084:coenzyme F420; D011765:Pyruvaldehyde; D000445:Aldehyde Oxidoreductases; C021493:lactaldehyde dehydrogenase; D005634:Fructose-Bisphosphate Aldolase; D012256:Riboflavin