The architecture of the gammadelta resolvase crossover site synaptic complex revealed by using constrained DNA substrates.
Activated mutants of the serine recombinase, gammadelta resolvase, form a simplified recombinogenic synaptic complex containing a tetramer of resolvase and two crossover sites. We have probed the architecture of this complex by measuring the efficiency of recombination of a series of constrained DNA substrates (with phased recombination sites separated by an IHF-induced U-turn); this serves as a direct report on the topology of a productive synapse. Our data show that in the active complex, the catalytic domains from two resolvase dimers form a central core, while the DNA binding domains and the DNA lie on the outside. In addition, the crossover sites cross one another to form a local positive node. The implications of our data for the mechanism of strand exchange and the process of resolvase activation are discussed.
Leschziner
Andres E
AE
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
Grindley
Nigel D F
ND
D001665:Binding Sites / Q000235:genetics; D020134:Catalytic Domain / Q000235:genetics; D023902:Chromosome Pairing / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication / Q000235:genetics*; D008958:Models, Molecular; D045522:Recombinases; D011995:Recombination, Genetic / Q000235:genetics*; D019895:Transposases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D045522:Recombinases; D004247:DNA; D019895:Transposases