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Title: Structural Basis for Catalytic Activation of a Serine Recombinase

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.
Authors:
; ; ; ;  [1] ;  [2]
  1. (Glasgow)
  2. (
Publication Date:
OSTI Identifier:
1027653
Resource Type:
Journal Article
Resource Relation:
Journal Name: Structure; Journal Volume: 19; Journal Issue: (6) ; 06, 2011
Research Org:
Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
Sponsoring Org:
OTHERNIH
Country of Publication:
United States
Language:
ENGLISH
Subject:
59 BASIC BIOLOGICAL SCIENCES; 60 APPLIED LIFE SCIENCES; CONFORMATIONAL CHANGES; CRYSTAL STRUCTURE; DNA; ENZYMES; PROTEINS; RESIDUES; SERINE