A specific N-terminal extension of the 8 kDa domain is required for DNA end-bridging by human Polμ and Polλ.

ABSTRACT: Human DNA polymerases mu (Polµ) and lambda (Polλ) are X family members involved in the repair of double-strand breaks in DNA during non-homologous end joining. Crucial abilities of these enzymes include bridging of the two 3' single-stranded overhangs and trans-polymerization using one 3' end as primer and the other as template, to minimize sequence loss. In this context, we have studied the importance of a previously uncharacterised sequence ('brooch'), located at the N-terminal boundary of the Polß-like polymerase core, and formed by Tyr(141), Ala(142), Cys(143), Gln(144) and Arg(145) in Polµ, and by Trp(239), Val(240), Cys(241), Ala(242) and Gln(243) in Polλ. The brooch is potentially implicated in the maintenance of a closed conformation throughout the catalytic cycle, and our studies

SUBMITTER: Martin MJ 

PROVIDER: S-EPMC3799444 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature