The run-on oligomer filament enzyme mechanism of SgrAI: Part 2. Kinetic modeling of the full DNA cleavage pathway.

ABSTRACT: Filament or run-on oligomer formation by enzymes is now recognized as a widespread phenomenon with potentially unique enzyme regulatory properties and biological roles. SgrAI is an allosteric type II restriction endonuclease that forms run-on oligomeric filaments with activated DNA cleavage activity and altered DNA sequence specificity. In this two-part work, we measure individual steps in the run-on oligomer filament mechanism to address specific questions of cooperativity, trapping, filament growth mechanisms, and sequestration of activity using fluorophore-labeled DNA, kinetic FRET measurements, and reaction modeling with global data fitting. The final models and rate constants show that the assembly step involving association of SgrAI-DNA complexes into the run-on oligomer filament is

SUBMITTER: Park CK 

PROVIDER: S-EPMC6153286 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature