Homology of the NifS family of proteins to a new class of pyridoxal phosphate-dependent enzymes

FEBS Lett. 1993 May 10;322(2):159-64. doi: 10.1016/0014-5793(93)81559-i.


Iterative profile sequence analysis reveals a remote homology of peroxisomal serine-pyruvate aminotransferases from mammals to the small subunit of soluble hydrogenases from cyanobacteria, an isopenicillin N epimerase, the NifS gene products from bacteria and yeast, and the phosphoserine aminotransferase family. All members of this new class whose function is known are pyridoxal phosphate-dependent enzymes, yet they have distinct catalytic activities. Upon alignment, a lysine around position 200 remains invariant and is predicted to be the pyridoxal phosphate-binding residue. Based on the detected homology, it is predicted that NifS has also a pyridoxal phosphate-dependent serine (or related) aminotransferase function associated with nitrogen economy and/or protection during nitrogen fixation.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / chemistry*
  • Databases, Factual
  • Humans
  • Molecular Sequence Data
  • Nitrogen Fixation / genetics
  • Pyridoxal Phosphate / physiology*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transaminases / chemistry
  • Transaminases / classification*


  • Bacterial Proteins
  • nifS protein, Bacteria
  • Pyridoxal Phosphate
  • Transaminases
  • serine-pyruvate aminotransferase