Implications of Structures of Synaptic Tetramers of gamma delta Resolvase for the Mechanism of Recombination
The structures of two mutants of the site-specific recombinase, {gamma}{delta} resolvase, that form activated tetramers have been determined. One, at 3.5-Angstroms resolution, forms a synaptic intermediate of resolvase that is covalently linked to two cleaved DNAs, whereas the other is of an unliganded structure determined at 2.1-Angstroms resolution. Comparisons of the four known tetrameric resolvase structures show that the subunits interact through the formation of a common core of four helices. The N-terminal halves of these helices superimpose well on each other, whereas the orientations of their C termini are more variable. The catalytic domains of resolvase in the unliganded structure are arranged asymmetrically, demonstrating that their positions can move substantially while preserving the four-helix core that forms the tetramer. These results suggest that the precleavage synaptic tetramer of {gamma}{delta} resolvase, whose structure is not known, may be formed by a similar four-helix core, but differ in the relative orientations of its catalytic and DNA-binding domains.
- Research Organization:
- Brookhaven National Laboratory (BNL) National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 914138
- Report Number(s):
- BNL--78706-2007-JA
- Journal Information:
- Proc Natl Acad Sci USA, Journal Name: Proc Natl Acad Sci USA Journal Issue: 28 Vol. 103; ISSN PNASA6; ISSN 0027-8424
- Country of Publication:
- United States
- Language:
- English
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