DNA Polymerase:
An Adaptation of Rumpelstiltskin
The function of a DNA polymerase is a fairly easy concept to grasp. DNA polymerases are the genetic copy machine of the cell. Essentially, the DNA polymerase creates a favorable environment for new nucleotides to attach to a template strand of DNA. Through analogies and simple terms, the general function of this essential enzyme can be relayed to children in a form comprehendible to them. In a cell, DNA polymerases can only function with their co-factor which helps the polymerase change conformation shape so that it conforms tighter to the template DNA. DNA polymerases are a type of holoenzyme because they require a magnesium ion to function correctly. When I was thinking of DNA polymerases function, I had a picture in mind of a polymerase “weaving” the DNA. So I decided to use that metaphor to convey the fluidity of a polymerase’s function. Using that simile, I decided to write an adaptation of Rumpelstiltskin for my children’s story. The story is intended to show the importance of a co-factor as well as describe the function of a polymerase. In the story, Poly, the polymerase, replaces the daughter in Rumpelstiltskin that is locked in the tower. Maggie, the magnesium ion, is the “dwarf” of the story. Poly is presented a dilemma where she must weave 20 new strands of DNA so that the king will marry her. Unfortunately she cannot do such things without her co-factor, so Maggie has to come and save the day.
Above the illustrations are the actual shapes of the enzyme, DNA polymerase and my creative representations of Poly and Maggie. DNA polymerases are comprised of three sections: a palm, thumb, and finger region. The enzyme resembles a hand so I made the cartoon of Poly look much like a hand. The magnesium ion is the smaller picture of the two. .
My children story goes as follows.
Poly the Polymerase
Long, long ago lived a polymerase named Poly who lived in a cell deep inside of a human’s body. She was the fairest of all polymerase children, but belonged to a poor family. Her father, Pete loved her dearly, but was more concerned with the money he owed to other polymerases in the land. Her father needed to find a way to pay off his debts even if it included using his daughter to get it. Luckily the king of the cell had lost his wife due too an unfortunate point mutation. So it was Peter’s chance to marry off his most beautiful daughter to the king raising his family out of poverty.
As soon as news reached the villages of the cell, every eligible girl polymerase began presenting themselves to the king. There were polymerases from all around showing off their talents. However, Poly had nothing special to offer besides her good looks. So one day Peter decided to go talk to the king himself and convince him to marry his daughter.
Peter marched to the front door of the king’s estate demanding to see his majesty. Finally, he convinced the guards to let him have a meeting with the king.
“Your majesty, marry my daughter. She is the most beautiful polymerase in all the land” said Peter.
“I am sorry sire. Your love and devotion to your daughter will not sway me to marry her. She needs to have more qualities that can help our kingdom. She needs something that sets her apart from other girls” replied the king.
Peter was stuck in a sticky situation. He could either lie about his daughter making the king want to marry her or just tell the truth and ruin her chances of becoming queen. His selfish motive kept nagging him in his mind. He must find some way to pay off his debts. This was his only chance.
“My daughter is the best DNA weaver in the cell.”
“Wow. Now that is an amazing characteristic. That could benefit our cell greatly. Good DNA weavers are hard to come by. She must prove to me she is worthy to be queen. If she can produce twenty copies of our cell’s DNA in one fortnight, I will marry her the next day” offered the king.
Peter rushed home to tell his daughter the good news. The only problem was Poly was not a reputable DNA weaver. Poly could not do much at all as a matter of fact. DNA was the most valuable thing in the entire cell kingdom. Only very special polymerases were able to weave such precious materials. DNA holds all information for everything in the cell.
“But father I cannot weave DNA. I will just marry Rudy the ribosome. Even though he is just a farm boy, we have love to keep us together” said Poly.
“I do not care what you think. You will weave DNA and marry the king” demanded Peter. So Peter took his daughter and locked her in the nucleus which holds all the DNA of the cell. “You have to weave 20 new strands or I will have you sent into exile in a vesicle. If the king finds out I am a liar, he will have me and you sent to the lysosome and hydrolyzed. Do you want that to happen to your dear old dad? ”
“O no!” gasped Poly “What shall I do?”
Poly sat in the dark nucleus through the night contemplating her problem. She was doomed to be banished from the cell forever or worse she and her dad would face a terrible end. Suddenly, a small ion appeared out of nowhere.
“Hi, I am a magnesium ion. I am here to help you weave that DNA” said the small element.
“But how will you help me I cannot weave DNA. I cannot even put my hand around the DNA.”
“Do not worry. I am your co-factor” replied the ion “I help by binding to you so you can change shape to where you can weave the DNA. This is called changing conformation shape.”
The ion helped Poly through the night weaving 20 new strands of DNA.
“Thank you so much! I am truly indebted to you. What can I do to repay you?” asked Poly.
“Well” replied the ion, “You must give me a room in your castle and then allow me to work with your children.”
“But I do not know if the king will just let a stranger live in his castle” said Poly “And as for my children, I would never just let you use them like that.”
“You must do so or I will destroy your new DNA” replied the ion.
Then the ion decided to pose a riddle for Poly to solve in order to rid herself of the duties the ion was demanding.
“If you can guess my name before you marry the king, I will allow you to get off free” said the ion.
The ion laughed as she left the nucleus knowing that neither Poly nor anyone could come up with the name Mumpelstilmembrane.
So Poly was left again with an undetermined fate. If she asked her new husband for a stranger to live in their house and use their children to make DNA, she knew he would reject her. Then Poly heard some noise from outside the nucleus. She pressed her ear against the nuclear envelope to hear what the ruckus was about. She could distinguish the voice of that strange ion among some other elemental ions such as hydrogen and oxygen.
“Yeah, I helped her weave the DNA. She is such a fool. I am basically guaranteed a room in the castle and the use of her children to make DNA” said the ion.
“Hahahaha” laughed the other ions.
“I told her if she could guess that my name was Mumpelstilmembrane before the king comes to get her, I would just leave her alone.”
Later that day, the ion reappeared in the nucleus.
“Well did you figure out what my name is?” asked the ion.
“Yes, I did. It is Mumpelstilmembrane” said Poly with confidence.
“O no!” gasped Mumpelstilmembrane, “How did you figure that out? O well. You realize you need me anyways. The king is going to want you to weave more DNA in the future.”
“That is true”
Poly thought long and hard of her situation. She then decided to allow Mumpelstilmembrane to stay and help her in the future, but the ion must hide in the castle and only come when Poly needs help.
The next day, Peter came to retrieve his daughter and to his surprise she completed the task. She was married the king. They all lived happily ever after together creating new DNA and running the kingdom of the cell.
After a few years, the children of Poly and the king took over the cell’s weaving of new DNA. They worked much faster at making new DNA than the other polymerases in the land. Because of the mysterious Mumpelstilmembrane ion, they were able to weave DNA more efficiently.
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