The monomeric GIY-YIG homing endonuclease I-BmoI uses a molecular anchor and a flexible tether to sequentially nick DNA.

ABSTRACT: The GIY-YIG nuclease domain is found within protein scaffolds that participate in diverse cellular pathways and contains a single active site that hydrolyzes DNA by a one-metal ion mechanism. GIY-YIG homing endonucleases (GIY-HEs) are two-domain proteins with N-terminal GIY-YIG nuclease domains connected to C-terminal DNA-binding and they are thought to function as monomers. Using I-BmoI as a model GIY-HE, we test mechanisms by which the single active site is used to generate a double-strand break. We show that I-BmoI is partially disordered in the absence of substrate, and that the GIY-YIG domain alone has weak affinity for DNA. Significantly, we show that I-BmoI functions as a monomer at all steps of the reaction pathway and does not transiently dimerize or use sequential transesterifica

SUBMITTER: Kleinstiver BP 

PROVIDER: S-EPMC3664794 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature