3hqg
From Proteopedia
Crystal structure of restriction endonuclease EcoRII catalytic C-terminal domain in complex with cognate DNA
Structural highlights
FunctionT2E2_ECOLX Recognizes the double-stranded sequence CCWGG and cleaves before C-1. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedEcoRII 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 the target site asymmetrically in a single defined orientation which is determined by specific hydrogen bonding and van der Waals interactions with the central T:A pair in the major groove. The EcoRII-N mode of the target site recognition is shared by the large class of higher plant transcription factors of the B3 superfamily. Structural mechanisms for the 5'-CCWGG sequence recognition by the N- and C-terminal domains of EcoRII.,Golovenko D, Manakova E, Tamulaitiene G, Grazulis S, Siksnys V Nucleic Acids Res. 2009 Oct;37(19):6613-24. Epub 2009 Sep 3. PMID:19729506[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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