text: Yo, check it out, let me break it down,
  The reaction catalyzed by N10-formyltetrahydrofolate synthetase, hold your ground,
  It starts with formyl phosphate, an intermediate in the mix,
  Formylates tetrahydrofolate, at the N-10 position, that's the fix.
  
  Previous studies showed the non-enzymic formylation's got a groove,
  5-nitrogen in the pyrazine ring, it's the spot to move,
  But we wondered if N5-formyltetrahydrofolate was first in line,
  Followed by formyl transfer, gettin' all sublime.
  
  A cyclic intermediate, N5,10-methenyltetrahydrofolate is the name,
  Could it be the pathway to the enzyme's claim to fame?
  We ran some experiments, had to find out the truth,
  Mixing [16O]H2O and [18O]H2O, that's the move.
  
  Using 13C NMR spectroscopy, we made it clear,
  No 18O in the product, no need to fear,
  The reaction goes direct, no fancy twists or bends,
  Formyl phosphate's the boss, at the N-10 position it sends.
  
  So there you have it, the facts are laid out,
  N10-formyltetrahydrofolate synthetase, there's no doubt,
  Formyl phosphate does its thing, no need for oxygen from the start,
  Straight formylation at N-10, that's the key to this art.