1rh6
From Proteopedia
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Bacteriophage Lambda Excisionase (Xis)-DNA Complex
Overview
The excisionase (Xis) protein from bacteriophage lambda is the best, characterized member of a large family of recombination directionality, factors that control integrase-mediated DNA rearrangements. It triggers, phage excision by cooperatively binding to sites X1 and X2 within the, phage, bending DNA significantly and recruiting the phage-encoded, integrase (Int) protein to site P2. We have determined the co-crystal, structure of Xis with its X2 DNA-binding site at 1.7A resolution. Xis, forms a unique winged-helix motif that interacts with the major and minor, grooves of its binding site using an alpha-helix and an ordered, beta-hairpin (wing), respectively. Recognition is achieved through an, elaborate water-mediated hydrogen-bonding network at the major groove, interface, while the preformed hairpin forms largely non-specific, interactions with the minor groove. The structure of the complex provides, insights into how Xis recruits Int cooperatively, and suggests a plausible, mechanism by which it may distort longer DNA fragments significantly. It, reveals a surface on the protein that is likely to mediate Xis-Xis, interactions required for its cooperative binding to DNA.
About this Structure
1RH6 is a Single protein structure of sequence from Enterobacteria phage lambda. Full crystallographic information is available from OCA.
Reference
Crystal structure of the excisionase-DNA complex from bacteriophage lambda., Sam MD, Cascio D, Johnson RC, Clubb RT, J Mol Biol. 2004 Apr 23;338(2):229-40. PMID:15066428
Page seeded by OCA on Wed Nov 21 01:35:41 2007
