AI Article Synopsis

  • Xis is a special protein that helps bend DNA and decides how DNA gets mixed up during a process called recombination.* -
  • There are likely four spots on the DNA where Xis can attach, but scientists found that the Xis crystals have five parts that work together to create a bent shape.* -
  • In a virus called Pukovnik, Xis and another protein called Int can work together to help form structures that include parts of the DNA needed for this process.*

Article Abstract

The recombination directionality factor, Xis, is a DNA bending protein that determines the outcome of integrase-mediated site-specific recombination by redesign of higher-order protein-DNA architectures. Although the attachment site DNA of mycobacteriophage Pukovnik is likely to contain four sites for Xis binding, Xis crystals contain five subunits in the asymmetric unit, four of which align into a Xis filament and a fifth that is generated by an unusual domain swap. Extensive intersubunit contacts stabilize a bent filament-like arrangement with Xis monomers aligned head to tail. The structure implies a DNA bend of ~120°, which is in agreement with DNA bending measured in vitro. Formation of attR-containing intasomes requires only Int and Xis, distinguishing Pukovnik from lambda. Therefore, we conclude that, in Pukovnik, Xis-induced DNA bending is sufficient to promote intramolecular Int-mediated bridges during intasome formation.

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Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3902635PMC
http://dx.doi.org/10.1016/j.jmb.2013.10.002DOI Listing

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