title: Non-equivalent interactions between amino-terminal domains of neighboring lambda integrase protomers direct Holliday junction resolution.
abstract: The bacteriophage lambda site-specific recombinase (Int), in contrast to other family members such as Cre and Flp, has an amino-terminal domain that binds "arm-type" DNA sequences different and distant from those involved in strand exchange. This defining feature of the heterobivalent recombinases confers a directionality and regulation that is unique among all recombination pathways. We show that the amino-terminal domain is not a simple "accessory" element, as originally thought, but rather is incorporated into the core of the recombination mechanism, where it is well positioned to exert its profound effects. The results reveal an unexpected pattern of intermolecular interactions between the amino-terminal domain of one protomer and the linker region of its neighbor within the tetrameric Int complex and provide insights into those features distinguishing an "active" from an "inactive" pair of Ints during Holliday junction resolution.
authors.affiliation: Division of Biology and Medicine, Brown University, 69 Brown Street, Providence, RI 02912, USA.
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
authors.forename: Marta
authors.initials: M
authors.lastname: Radman-Livaja
authors.forename: David
authors.initials: D
authors.lastname: Warren
authors.forename: Hideki
authors.initials: H
authors.lastname: Aihara
authors.forename: Tom
authors.initials: T
authors.lastname: Ellenberger
authors.forename: Arthur
authors.initials: A
authors.lastname: Landy
mesh_terms: D000483:Alleles; D010582:Bacteriophage lambda / Q000201:enzymology*; D001483:Base Sequence; D017931:DNA Primers; D045566:DNA, Cruciform; D019426:Integrases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D045566:DNA, Cruciform; D019426:Integrases