5u96

Publication Abstract from PubMed

Serine integrases catalyze the integration of bacteriophage DNA into a host genome by site-specific recombination between 'attachment sites' in the phage (attP) and the host (attB). The reaction is highly directional; the reverse excision reaction between the product attL and attR sites does not occur in the absence of a phage-encoded factor, nor does recombination occur between other pairings of attachment sites. A mechanistic understanding of how these enzymes achieve site-selectivity and directionality has been limited by a lack of structural models. Here, we report the structure of the C-terminal domains of a serine integrase bound to an attP DNA half-site. The structure leads directly to models for understanding how the integrase-bound attP and attB sites differ, why these enzymes preferentially form attP x attB synaptic complexes to initiate recombination, and how attL x attR recombination is prevented. In these models, different domain organizations on attP vs. attB half-sites allow attachment-site specific interactions to form between integrase subunits via an unusual protruding coiled-coil motif. These interactions are used to preferentially synapse integrase-bound attP and attB and inhibit synapsis of integrase-bound attL and attR. The results provide a structural framework for understanding, testing and engineering serine integrase function.

Attachment site recognition and regulation of directionality by the serine integrases.,Rutherford K, Yuan P, Perry K, Sharp R, Van Duyne GD Nucleic Acids Res. 2013 Sep 1;41(17):8341-56. doi: 10.1093/nar/gkt580. Epub 2013 , Jul 2. PMID:23821671^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.