Helicase and Polymerase

This has got to be the most awesome pickup line ever, not only is it all “punny” and amusing but it basically tells someone exactly what DNA helicase does 😀

But…What is a helicase?

Helicases are enzymes which have the ability to bind, reshape and reformat nucleic acid or nucleic acid complexes. In nature there are DNA and RNA helicases.

DNA helicase:
DNA helicase is the key emzyme in the replication of DNA. How it works is that during DNA replication, this helicase binds to the DNA molecule and begins to unwind the helical structure at positions called origins. At these points synthesis of proteins begin. The DNA helix is unwinded due to the breaking of hydrogen bonds between the pyrimidine-purine, nucleotide base pairs. However to break these bonds, energy is required and is thus provided by ATP molecules. This helicase also has functions in, DNA repair and DNA transcription.

RNA helicase:

This enzyme participate in all RNA process specifically those which contain splicing, transcription and translation. Specificity or RNA helicase can depend on several factors, such as nucleotide sequence, interacting molecules and expression pattern of the helicase itself. PubMed provides a very adequate example of situations in which there may be RNA differentiation (see references). Like DNA helicase, its reactions is totally ATP-dependent.

Their opposite counterparts.

Since helicases have the ability to unwind a structure there must me something that has the ability to undo what it has done. I mean try to imagine your DNA just laying around in its cellular environment, prone to environmental factors, that is pretty dangerous!

DNA polymerase is an enzyme which catalyses polymerisation of deoxyneucleotides into DNA strand. Their major role lays in DNA replication. In replication, the enzyme has the ability to read a single strand of DNA and use free nucleotides to create its complementary strand. This process thus copies DNA

The Enzyme which rejoins and reforms the initial helical structure is known as DNA ligase.

A ligase is an enzyme which can catalyze the joining of two large molecules, to form a new molecule. This reaction usually involves the process of hydrolysis of a small chemical group. Ligases catalyses the joining of C-O, C-N, C-S.

DNA ligase begins by catalysing the formation of a phosphodiester bond along carbon 3 of the 5C ribose sugar.