Practice question

Formation and processing of Holliday junction is organized by RuvAB complex. RuvA is tetrameric DNA-binding protein with preference for four-way junction architecture over linear duplex. It forms sandwich with two concave surfaces contacting crossover center, forcing junction into open square-planar configuration exposing two duplex arms for RuvB loading. RuvA thus acts as specificity factor delivering junction-processing motor to correct DNA structure and prevents off-target translocation on regular duplex. Acidic C-terminal domain of RuvA recruits RuvB hexamers via interaction with domain II, orchestrating downstream branch migration.