Methyladeninylcobamide functions as the cofactor of methionine synthase in a Cyanobacterium, Spirulina platensis NIES-39

FEBS Lett. 2010 Jul 16;584(14):3223-6. doi: 10.1016/j.febslet.2010.06.013. Epub 2010 Jun 17.

Abstract

To clarify the physiological function of pseudovitamin B(12) (or adeninylcobamide; AdeCba) in Spirulina platensis NIES-39, cobalamin-dependent methionine synthase (MS) was characterized. We cloned the full-length Spirulina MS. The clone contained an open reading frame encoding a protein of 1183 amino acids with a molecular mass of 132 kDa. Deduced amino acid sequences of the Spirulina MS contained critical residues identical to cobalamin-, zinc-, S-adenosylmethionine-, and homocysteine-binding motifs. The recombinant Spirulina enzyme showed higher affinity for methyladeninylcobamide than methylcobalamin as a cofactor. These results indicate that Spirulina cells can utilize AdeCba synthesized as the cofactor for MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / chemistry
  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / genetics
  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / metabolism*
  • Amino Acid Sequence
  • Bacteria / genetics
  • Bacteria / metabolism
  • Cyanobacteria / genetics
  • Cyanobacteria / metabolism*
  • Inorganic Chemicals
  • Molecular Sequence Data
  • Organic Chemicals
  • Protein Structure, Tertiary / genetics
  • S-Adenosylmethionine / genetics
  • S-Adenosylmethionine / metabolism
  • Vitamin B 12 / analogs & derivatives
  • Vitamin B 12 / genetics
  • Vitamin B 12 / metabolism

Substances

  • Inorganic Chemicals
  • Organic Chemicals
  • S-Adenosylmethionine
  • mecobalamin
  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase
  • Vitamin B 12

Associated data

  • GENBANK/AB548759