16807292 , Related PDB ids: 2GM4, 2GM5
- Kamtekar S, Ho RS, Cocco MJ, Li W, Wenwieser SV, Boocock MR, Grindley ND, Steitz TA
- Implications of structures of synaptic tetramers of gamma delta resolvase for the mechanism of recombination.
- Proc Natl Acad Sci U S A. 2006 Jul 11;103(28):10642-7. Epub 2006 Jun 28.
- The structures of two mutants of the site-specific recombinase, gammadelta resolvase, that form activated tetramers have been determined. One, at 3.5-A 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-A 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 gammadelta 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.