Architecture of recombination intermediates visualized by in-gel FRET of lambda integrase-Holliday junction-arm DNA complexes.

ABSTRACT: Lambda integrase (Int) mediates recombination between attachment sites on phage and Escherichia coli DNA. Int is assisted by accessory protein-induced DNA loops in bridging pairs of distinct "arm-type" and "core-type" DNA sites to form synapsed recombination complexes that subsequently recombine by means of a Holliday junction (HJ) intermediate. An in-gel FRET assay was developed and used to measure 15 distances between six points in two Int-HJ complexes containing arm-DNA oligonucleotides, and 3D maps of these complexes were derived by distance-geometry calculations. The maps reveal unexpected positions for the arm-type DNAs relative to core sites on the HJ and a new Int conformation in the HJ tetramer. The results show how the position of arm DNAs determines the bias of catalytic activit

SUBMITTER: Radman-Livaja M 

PROVIDER: S-EPMC554831 | biostudies-literature | 2005 Mar

REPOSITORIES: biostudies-literature