Structural mechanisms for the 5'-CCWGG sequence recognition by the N- and C-terminal domains of EcoRII.

ABSTRACT: EcoRII restriction endonuclease is specific for the 5'-CCWGG sequence (W stands for A or T); however, it shows no activity on a single recognition site. To activate cleavage it requires binding of an additional target site as an allosteric effector. EcoRII dimer consists of three structural units: a central catalytic core, made from two copies of the C-terminal domain (EcoRII-C), and two N-terminal effector DNA binding domains (EcoRII-N). Here, we report DNA-bound EcoRII-N and EcoRII-C structures, which show that EcoRII combines two radically different structural mechanisms to interact with the effector and substrate DNA. The catalytic EcoRII-C dimer flips out the central T:A base pair and makes symmetric interactions with the CC:GG half-sites. The EcoRII-N effector domain monomer binds to

SUBMITTER: Golovenko D 

PROVIDER: S-EPMC2770665 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature