This SPRY domain is found at the N terminus of RING finger protein 123 (also known as E3 ubiquitin-protein ligase RNF123, KPC1). The ring finger domain motif is present in a variety of functionally distinct proteins and known to be involved in protein-protein and protein-DNA interactions. RNF123 displays E3 ubiquitin ligase activity toward the cyclin-dependent kinase inhibitor p27 (Kip1) []and p105 and inhibits tumor growth via regulation of p50-dependent tumor suppressor genes [].Proteins containing this domain also include AtKPC1 from Arabidopsis. AtKPC1 is an E3 ubiquitin-protein ligase that promotes the ubiquitination and proteasomal degradation of KRP1 and KRP2 [, ].
