Structural Basis for Catalytic Activation of a Serine Recombinase
- Glasgow
Sin resolvase is a site-specific serine recombinase that is normally controlled by a complex regulatory mechanism. A single mutation, Q115R, allows the enzyme to bypass the entire regulatory apparatus, such that no accessory proteins or DNA sites are required. Here, we present a 1.86 {angstrom} crystal structure of the Sin Q115R catalytic domain, in a tetrameric arrangement stabilized by an interaction between Arg115 residues on neighboring subunits. The subunits have undergone significant conformational changes from the inactive dimeric state previously reported. The structure provides a new high-resolution view of a serine recombinase active site that is apparently fully assembled, suggesting roles for the conserved active site residues. The structure also suggests how the dimer-tetramer transition is coupled to assembly of the active site. The tetramer is captured in a different rotational substate than that seen in previous hyperactive serine recombinase structures, and unbroken crossover site DNA can be readily modeled into its active sites.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- OTHERNIH
- OSTI ID:
- 1027653
- Journal Information:
- Structure, Vol. 19, Issue (6) ; 06, 2011
- Country of Publication:
- United States
- Language:
- ENGLISH
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