This domain represents the N-terminal region of the E3 ubiquitin-protein ligase RKP from plants. It was demonstrated that RKP is a functional ubiquitin E3 ligase and is able to interact with cell-cycle inhibitor ICK/KRP proteins.

1: RKP, a RING finger E3 ligase induced by BSCTV C4 protein, affects geminivirus infection by regulation of the plant cell cycle. Lai J, Chen H, Teng K, Zhao Q, Zhang Z, Li Y, Liang L, Xia R, Wu Y, Guo H, Xie Q; Plant J. 2009;57:905-917. PMID:19000158

2: Degradation of the cyclin-dependent kinase inhibitor KRP1 is regulated by two different ubiquitin E3 ligases. Ren H, Santner A, del Pozo JC, Murray JA, Estelle M; Plant J. 2008;53:705-716. PMID:18005227