Target DNA recognition and cleavage by a reconstituted Type I-G CRISPR-Cas immune effector complex.

ABSTRACT: CRISPR-Cas immune systems defend prokaryotes against viruses and plasmids. CRISPR RNAs (crRNAs) associate with various CRISPR-associated (Cas) protein modules to form structurally and functionally diverse (Type I-VI) crRNP immune effector complexes. Previously, we identified three, co-existing effector complexes in Pyrococcus furiosus -Type I-A (Csa), Type I-G (Cst), and Type III-B (Cmr)-and demonstrated that each complex functions in vivo to eliminate invader DNA. Here, we reconstitute functional Cst crRNP complexes in vitro from recombinant Cas proteins and synthetic crRNAs and investigate mechanisms of crRNP assembly and invader DNA recognition and destruction. All four known Cst-affiliated Cas proteins (Cas5t, Cst1, Cst2, and Cas3) are required for activity, but each subunit plays a di

SUBMITTER: Majumdar S 

PROVIDER: S-EPMC5404416 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature