1rh6
From Proteopedia
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| , resolution 1.70Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , | ||||||
| Gene: | xis (Enterobacteria phage lambda) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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 Sun Mar 30 23:28:06 2008
