text: Yo, check it out, let me break it down
  Talkin' 'bout the cII protein of phage lambda, hold your crown
  It's the key factor, no doubt, in the virus's choice
  To go lytic or lysogenic, hear my voice
  
  Previous research, it's been found and told
  That cII activity is controlled
  By the turnover of the cII protein, you see
  HflA and hflB loci of E. coli, they're the key
  
  They're needed for degradation, it's a fact
  While lambda cIII, it helps cII intact
  We got the cloned hflA locus, it's been done
  Purified an enzyme, HflA, we won
  
  HflA got three polypeptides, listen close
  Two from hflA region, the third, suppose
  It's a product of cleavage, from the larger of the two
  HflA protease, it's got work to do
  
  Cleaving cII into small fragments, that's the deal
  Switchin' lambda's pathways, it's for real
  Regulated cleavage, that's the game, no drama
  Specific protease HflA, it's the mama