Ligation = polymerisation ?

[Function]

Hi everyone

 

In preparation for my Molecular Biology & Genetics exam, following example question:

 

"Which of the following proteins polymerizes nucleotides in DNA?"

With 2 of the possible answers being "DNA-ligase" and "reverse transcriptase".

 

Intuitionally, I'd go for the last one. However, discussion arises with the question if it polymerizes "in" DNA, considering the transcription of RNA to DNA.

The big question of which the answer might solve the issue, is the following: can a ligation be put equal to a polymerisation? As in, if 2 or more nucleotides are bound, can one say that they are polymerized? (Which is the case for okazaki frags.)

 

Thanks in advance!

 

F.

Edited June 19, 2015 by Function

[hypervalent_iodine]

The process of polymerization is usually defined as the joining of monomers to form some sort of continuous structure. In this case, you could say that the product is a polymer (though 2 nucleotides wouldn't really count as one), but I wouldn't really call the rejoining of two fragments a polymerization reaction.

[CharonY]

Actually I would not be that sure. I have seen ligation of oligonucleotides referred to as polymerization. The most common example being in vitro use, such as joining of various templates or creation of functionalized polymers.

The wording is tricky but I would probably allow both answers as, (to my knowledge) the term is typically not used in an extremely narrow sense.

[Function]

Thanks for your inputs indeed. If he's to ask the question on the exam Tuesday, I'll make sure to try ask him if he considers ligation a polymerization.