What enzymes are proofreading DNA?

What enzymes are proofreading DNA?

DNA polymerases are the enzymes that build DNA in cells. During DNA replication (copying), most DNA polymerases can check their work with each base that they add. This process is called proofreading.

What is the main DNA polymerase enzyme in prokaryotes?

In prokaryotes, three main types of polymerases are known: DNA pol I, DNA pol II, and DNA pol III. It is now known that DNA pol III is the enzyme required for DNA synthesis; DNA pol I and DNA pol II are primarily required for repair.

Which prokaryotic DNA polymerase has proofreading activity?

In bacteria, all three DNA polymerases (I, II and III) have the ability to proofread, using 3′ 5′ exonuclease activity. When an incorrect base pair is recognized, DNA polymerase reverses its direction by one base pair of DNA and excises the mismatched base.

Why is RNA used instead of DNA?

Due to its deoxyribose sugar, which contains one less oxygen-containing hydroxyl group, DNA is a more stable molecule than RNA, which is useful for a molecule which has the task of keeping genetic information safe. RNA, containing a ribose sugar, is more reactive than DNA and is not stable in alkaline conditions.

What is the difference between DNA and RNA sequence?

Like DNA, RNA is made up of nucleotides. There are two differences that distinguish DNA from RNA: (a) RNA contains the sugar ribose, while DNA contains the slightly different sugar deoxyribose (a type of ribose that lacks one oxygen atom), and (b) RNA has the nucleobase uracil while DNA contains thymine.