N5 ,N10 -methylenetetrahydromethanopterin reductase from Methanocaldococcus jannaschii also serves as a methylglyoxal reductase

FEBS Lett. 2017 Aug;591(15):2269-2278. doi: 10.1002/1873-3468.12728. Epub 2017 Jul 13.

Abstract

In Methanocaldococcus jannaschii, methylglyoxal (MG) is required for aromatic amino acid biosynthesis. Previously, the reduction of MG to lactaldehyde in Methanocaldococcus jannaschii cell extracts using either NADPH or F420 H2 was demonstrated; however, the enzyme responsible was not identified. Using NADPH as the reductant, the unknown enzyme was purified from cell extracts of Methanocaldococcus jannaschii and determined to be the F420 -dependent N5 ,N10 -methylenetetrahydromethanopterin reductase (Mer). Here, we report that the recombinantly overexpressed Mer is able to use NADPH and MG (KM of 1.6 and 1.0 mm, respectively) to produce lactaldehyde. Additionally, Mer does not catalyze the reduction of MG to lactaldehyde in the presence of reduced Fo, the precursor of F420 .

Keywords: enzyme promiscuity; lactaldehyde; methanogen; methylglyoxal.

Publication types

  • Letter

MeSH terms

  • Alcohol Oxidoreductases / metabolism*
  • Aldehydes / metabolism
  • Archaeal Proteins / genetics
  • Archaeal Proteins / metabolism
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Methanocaldococcus / enzymology*
  • Methanocaldococcus / metabolism
  • NADP / metabolism
  • Oxidoreductases Acting on CH-NH Group Donors / genetics
  • Oxidoreductases Acting on CH-NH Group Donors / metabolism*
  • Pyruvaldehyde / metabolism
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism

Substances

  • Aldehydes
  • Archaeal Proteins
  • Recombinant Proteins
  • NADP
  • lactaldehyde
  • Pyruvaldehyde
  • Alcohol Oxidoreductases
  • D-lactaldehyde dehydrogenase
  • Oxidoreductases Acting on CH-NH Group Donors
  • methylenetetrahydromethanopterin dehydrogenase