BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 15 (KLHL15)
KLHL15 is a substrate-specific adaptor for the Cullin3 E3 ubiquitin-protein ligase complex that targets the serine/threonine-protein phosphatase 2A (PP2A) subunit PPP2R5B for ubiquitination and subsequent proteasomal degradation, thus promoting exchange with other regulatory subunits. It also plays a key role in DNA damage response, favoring DNA double-strand repair through error-prone non-homologous end joining (NHEJ) over error-free, RBBP8-mediated homologous recombination (HR), by targeting the DNA-end resection factor RBBP8/CtIP for ubiquitination and subsequent proteasomal degradation. KLHL15 contains a BTB domain and kelch repeats, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.
Jiyao W et al.(2023). "The conserved domain database in 2023.",