DNA poe(m)

Authors


  • Once upon a G phase dreary, while I pondered weak and weary,

  • Over many a quaint and curious volume of deoxy lore,

  • While I nodded, nearly napping, suddenly there came a tapping,

  • As of someone gently rapping, rapping at my helical core.

  • ‘Tis some visitor,’ I muttered, ‘tapping at my helical core -

  • Tapping that I can't ignore.’

  • It was in the Homo genus, when the S phase was upon us,

  • Bonds of hydrogen, not so strong now, kept the base pairs

  • core to core.

  • Adenine twice paired to Thymine; Cytosine thrice paired to Guanine,

  • Helix to helix, purine to pyrimidine, mirroring forevermore.

  • Phosphodiester at the backbone holds this image forevermore,

  • But what else might lie in store?

  • 'Twas a protein: DnaA, entering to separate

  • These two strands that seemingly had never been apart before.

  • Fearing loss of unification, suddenly I had a vision:

  • ‘A polypeptide seeking entrance, entrance to my helical core -

  • Enterprising friendly enzyme seeking for my helical core -

  • This it is, and nothing more.’

  • A gap has formed, I am unwinding!

  • Enzymatic entities come rushing through my open door,

  • Oh! DNA helicases, moving to my secret places,

  • Working to unwind me, am I a prisoner of war?

  • Strand from strand pulled hand by hand, I'm sure not

  • sleepy anymore,

  • Even though I was before.

  • Single stranded binding proteins attach themselves along my genes,

  • Providing for enzymes that hadn't been allowed before.

  • Topoisomerases release my strands from tight embraces,

  • Easing the tense supercoils that would have run along my core.

  • ATP is a requirement, needed to complete the chore,

  • Quoth the enzymes: ‘We want more!’

  • I'm exposed, it is so awkward, flippy floppy single stranded;

  • Longing sadly for the double stranded days of yore.

  • But what is this? I see a primer, RNA and nothing finer,

  • Moving up into my crotch, such a movement I deplore.

  • Ah! it stops, as luck would have it, anneals itself along my core,

  • Antiparallel and nothing more.

  • I need some healing; I need concealing,

  • Surely someone can discover salves to heal and cure my sore.

  • Not the deadly Amanita! I need DNA polymerase delta,

  • Affixing itself onto the primer, which otherwise I would ignore.

  • 5′ to 3′ operation; covering up my open sore.

  • Quoth the enzyme, ‘I can do more!’

  • The enzyme works in such a hurry, causing me to fret and worry

  • Adenine shouldn't be with Guanine, these errors I do deplore.

  • Pol delta has a trick or two, surely it knows what to do.

  • Its exonuclease removes the base, 3′ to 5′ and nothing more.

  • Finding all its own mistakes, this enzyme is no sophomore.

  • Proofreading effects a speedy cure.

  • Okazaki! Okazaki!

  • Lagging strand, so intermittent, fragments line my inner core.

  • RNA you are a stranger, you're in clear and present danger.

  • FEN and Ribonuclease cut, throwing litter on the floor.

  • Polymerase come fill the gaps! Gaps that no one should ignore.

  • Quoth the enzymes: ‘There is more’.

  • Leading strand you were so easy, lagging strand you make

  • me queasy!

  • Tiny nicks remain from enzymatic work that's come before.

  • 3′ hydroxyl, 5′ phosphate, is separation your lasting fate?

  • DNA ligase to the rescue, ‘mind the gaps’, my paramour!

  • ATP is a requirement, love's not cheap, not anymore.

  • Quoth the enzymes: ‘There is no more!’

  • Where once was one, there now are two; Mitosis is the thing to do!

  • What beautiful twin daughters! Blessed with stellar Apgar scores.

  • Still, we left some stones unturnéd in our attempt to be

  • more learnéd

  • Telomerase is unexplored; it doesn't wish to be ignored,

  • Transcription and translation, too, lie upon a distant shore

  • Quoth the enzymes, ‘We said, no more!’

  • And the helix, never spoiling, still is coiling, still is coiling!

  • In the naked nuclear depths, the cytoplasm I deplore;

  • And hidden deep within my coils, information never spoils,

  • The splendid light of DNA shines on all I could not explain before.

  • There is grandeur in this view of life, this precious life we all adore,

  • Dividing still forevermore.

Ancillary