{Reference Type}: Journal Article {Title}: A glimpse into the hidden world of the flexible C-terminal protein binding domains of human RAD52. {Author}: Struble LR;Lovelace JJ;Borgstahl GEO; {Journal}: J Struct Biol {Volume}: 216 {Issue}: 3 {Year}: 2024 Sep 6 {Factor}: 3.234 {DOI}: 10.1016/j.jsb.2024.108115 {Abstract}: Human RAD52 protein binds DNA and is involved in genomic stability maintenance and several forms of DNA repair, including homologous recombination and single-strand annealing. Despite its importance, there are very few structural details about the variability of the RAD52 ring size and the RAD52 C-terminal protein-protein interaction domains. Even recent attempts to employ cryogenic electron microscopy (cryoEM) methods on full-length yeast and human RAD52 do not reveal interpretable structures for the C-terminal half that contains the replication protein A (RPA) and RAD51 binding domains. In this study, we employed the monodisperse purification of two RAD52 deletion constructs and small angle X-ray scattering (SAXS) to construct a structural model that includes RAD52's RPA binding domain. This model is of interest to DNA repair specialists as well as for drug development against HR-deficient cancers.