text: Yo, listen up, I got some knowledge to drop,
  About DNA topoisomerase IV, it won't flop.
  It removes unwanted twists from DNA strands,
  To keep those chromosomes in stable hands.
  
  We got two constructs, check the size, y'all,
  One's 56 kDa, the other's 59, stand tall.
  They span the DNA-cleavage domain, no doubt,
  Of the A subunit from Staphylococcus aureus, shout it out!
  
  GrlA56 and GrlA59, that's what they're called,
  Crystallized like diamonds, they're standin' tall.
  Grew 'em at 291 K, with a vapor-diffusion play,
  Using PEG 3350, as a precipitant, okay?
  
  Preliminary X-ray analysis, let me paint the scene,
  GrlA56 crystals in space group P2(1), so serene.
  They diffract at 2.9 A, that's a resolution so fine,
  Unit-cell parameters, a = 83.6, b = 171.5, c = 87.8, that's the sign.
  
  Now let's talk about GrlA59, a different groove,
  Space group P2(1)2(1)2, that's the move.
  Unit-cell parameters, a = 41.5, b = 171.89, c = 87.9 A,
  Diffracting at 2.8 A, it's time to play.
  
  This report's a first, a groundbreaking hit,
  Crystallization and X-ray analysis, ain't that legit?
  We're talkin' topoisomerase IV from Gram-positive,
  Ain't no other organism that can provide this.
  
  So there you have it, the facts straight,
  In a rap style, no need to debate.
  DNA topoisomerase IV, crystalized and analyzed,
  Keeping chromosomes stable, yo, we're mesmerized!