|
|
|
![]() Other Issues: |
|
||||||
Model of the Hin invertasome that assembles during
site-specific DNA inversion. Hin recombinase dimers bind to each of the two recombination sites hixL and hixR, and Fis
dimers bind to two sites within the recombinational enhancer segment.
The three segments assemble into an invertasome structure at the base
of a DNA branch on supercoiled DNA. Within this structure, Fis
activates the catalytic properties of Hin to initiate recombination.
(Top left) Schematic representation of the invertasome
assembled on a plasmid substrate; (top right) molecular
model of Fis bound to the two enhancer domains. The side chains of the
three amino acids within the mobile Fis
-hairpin arms (highlighted
in pink) that are critical for activating Hin are shown. Only one of
the
-hairpin arms is required to activate Hin. (Bottom)
Molecular model of the invertasome. The enhancer segment has been
rotated approximately 90° about the z axis in comparison
to the top right. (For details, see Merickel et al., p.
2803.)