Distance determination by GIY-YIG intron endonucleases: discrimination between repression and cleavage functions.

ABSTRACT: GIY-YIG homing endonucleases are modular proteins, with conserved N-terminal catalytic domains connected by linkers to C-terminal DNA-binding domains. I-TevI, the T4 phage GIY-YIG intron endonuclease, functions both in promoting td intron homing, and in acting as a transcriptional autorepressor. Repression is achieved by binding to an operator, which is cleaved at 100-fold reduced efficiency relative to the intronless homing site. The linker includes a zinc finger, which functions in distance determination, to constrain the catalytic domain to cleave the homing site at a fixed position. Here we show that I-BmoI, a related GIY-YIG endonuclease lacking a zinc finger, also possesses some cleavage distance discrimination. Furthermore, hybrid endonucleases constructed by swapping the domains of

SUBMITTER: Liu Q 

PROVIDER: S-EPMC1421500 | biostudies-literature | 2006

REPOSITORIES: biostudies-literature