1es8
From Proteopedia
CRYSTAL STRUCTURE OF FREE BGLII
Overview
Restriction endonuclease BglII completely encircles its target DNA, making contacts to both the major and minor grooves. To allow the DNA to enter and leave the binding cleft, the enzyme dimer has to rearrange. To understand how this occurs, we have solved the structure of the free enzyme at 2.3 A resolution, as a complement to our earlier work on the BglII-DNA complex. Unexpectedly, the enzyme opens by a dramatic 'scissor-like' motion, accompanied by a complete rearrangement of the alpha-helices at the dimer interface. Moreover, within each monomer, a set of residues--a 'lever'--lowers or raises to alternately sequester or expose the active site residues. Such an extreme difference in free versus complexed structures has not been reported for other restriction endonucleases. This elegant mechanism for capturing DNA may extend to other enzymes that encircle DNA.
About this Structure
1ES8 is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
Structure of free BglII reveals an unprecedented scissor-like motion for opening an endonuclease., Lukacs CM, Kucera R, Schildkraut I, Aggarwal AK, Nat Struct Biol. 2001 Feb;8(2):126-30. PMID:11175900 Page seeded by OCA on Fri May 2 15:27:40 2008
