Biology Reference
In-Depth Information
UvrA
2
B
2
locates the
DNA damage
UvrB
3
5
3
UvrB
5
UvrA
2
UvrA
2
is ejected.
The pre-incision
complex is
formed
UvrC binds and
nicks the DNA
UvrC
UvrD releases the
damaged oligo and
DNA Pol l begins
resynthesis
UvrD
5
3
3
5
DNA Pol l
DNA Ligase seals
nicks
F
IG
. 1. Structural model of bacterial nucleotide excision repair mediated by six proteins. The
process of NER is a complex multiprotein cascade of events. Each step requires the recruitment of
another protein to the lesion, with UvrB remaining at the lesion site as it interacts with each
component of the reaction. Remarkably, despite this central role, UvrB is incapable of binding to
the lesion site directly, requiring loading by UvrA
2
.
alternative is that the UvrA
2
UvrB
2
-DNA complex and interaction interface
between the proteins is flexible enough to allow UvrB to clamp down onto the
DNA face opposite UvrA
2
in order to be positioned for a direct handoff of the
lesion.
2,18,19
In this model, UvrA
2
may bend the DNA to facilitate localized
