Dam (methylase)

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Dam methylase (DNA adenine methylase) adds a methyl group to the adenine of the sequence 5'-GATC-3'in newly synthesized DNA. Immediately after DNA synthesis, the daughter strand remains unmethylated for a short time and can be detected by DpnI, a restriction endonuclease that cuts around this GATC recognition sequence.

[edit] Role in mismatch repair of DNA

When DNA polymerase makes an error causing a mismatch during DNA synthesis, the cell must be able to differentiate the template strand from the newly synthesized strand. A repair enzyme, MutS, binds to the daughter strand by the transient absence of methylation on that strand. It then and recruits enzymes to repair it.

[edit] Related pages

• DNA replication
• methylase
• mismatch repair

[edit] External links

• http://fangman-brewer.genetics.washington.edu/hemimethylation.html