This is the C-terminal domain mainly found in E3 ubiquitin ligases. Proteolysis 6 (PRT6) encodes a ubiquitin E3 ligase belonging to the N-end rule pathway of targeted protein degradation, which is a specialised subset of the ubiquitin proteasome system [1]. In Arabidopsis, at least two N-recognins (E3 ubiquitin ligases) with different substrate specificities exist, namely PROTEOLYSIS1 (PRT1) and PRT6 [2].

1: Distinct branches of the N-end rule pathway modulate the plant immune response. Vicente J, Mendiondo GM, Pauwels J, Pastor V, Izquierdo Y, Naumann C, Movahedi M, Rooney D, Gibbs DJ, Smart K, Bachmair A, Gray JE, Dissmeyer N, Castresana C, Ray RV, Gevaert K, Holdsworth MJ; New Phytol. 2019;221:988-1000. PMID:30117535

2: The N-end rule pathway regulates pathogen responses in plants. de Marchi R, Sorel M, Mooney B, Fudal I, Goslin K, Kwasniewska K, Ryan PT, Pfalz M, Kroymann J, Pollmann S, Feechan A, Wellmer F, Rivas S, Graciet E; Sci Rep. 2016;6:26020. PMID:27173012