Analysis of the Intrinsically Disordered N-Terminus of the DNA Junction-Resolving Enzyme T7 Endonuclease I: Identification of Structure Formed upon DNA Binding.

ABSTRACT: The four-way (Holliday) DNA junction of homologous recombination is processed by the symmetrical cleavage of two strands by a nuclease. These junction-resolving enzymes bind to four-way junctions in dimeric form, distorting the structure of the junction in the process. Crystal structures of T7 endonuclease I have been determined as free protein, and the complex with a DNA junction. In neither crystal structure was the N-terminal 16-amino acid peptide visible, yet deletion of this peptide has a marked effect on the resolution process. Here we have investigated the N-terminal peptide by inclusion of spin-label probes at unique sites within this region, studied by electron paramagnetic resonance. Continuous wave experiments show that these labels are mobile in the free protein but become cons

SUBMITTER: Freeman AD 

PROVIDER: S-EPMC4990344 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature