Proofreading

Proofreading
The overall error rate during DNA replication in E.coli is one base in one million (106).
DNA polymerase proofreads the new strand of DNA as it is synthesized and it removes mismatched bases and replaces them with the correct bases.

Proofreading
Removal of mismatched base pairs during DNA replication by the 3' to 5' exonuclease activity of DNA polymerase, followed by resynthesis.
Protease
An enzyme that degrades proteins to peptides or amino acids.

"Transcript-assisted transcriptional proofreading.". Science. 313: 518-520. PMID 16873663.
^ Ibba M, Soll D. (2000). "Aminoacyl-tRNA synthesis.". Annu Rev Biochem. 69: 617-650. PMID 10966471.
^ Rodnina MV, Wintermeyer W. (2001).

A disadvantage of Taq is that it sometimes makes mistakes when copying DNA, leading to mutations (errors) in the DNA sequence, since it lacks 3'-5' proofreading exonuclease activity.

Mismatches of the normal bases because of a failure of proofreading during DNA replication.
Common example: incorporation of the pyrimidine U (normally found only in RNA) instead of T.

Each person writes her/his own paper but you should help one another by proofreading and editing. The paper should be no more than 4-6 double spaced pages.

DNA repair: Restoration of the correct nucleotide sequence of a DNA molecule that has acquired a mutation or modification. It includes proofreading by DNA polymerase (see helicase).

Approaches that (1) verify a previously determined DNA sequence's accuracy without having to redetermine its entire sequence and (2) provide economical error-checking and proofreading of newly determined DNA sequence.

See also: DNA, Trans, Cells, Gene, Genome