4npn

Publication Abstract from PubMed

The E3 ubiquitin ligase RNF4 (RING finger protein 4) contains four tandem SIM [SUMO (small ubiquitin-like modifier)-interaction motif] repeats for selective interaction with poly-SUMO-modified proteins, which it targets for degradation. We employed a multi-faceted approach to characterize the structure of the RNF4-SIMs domain and the tetra-SUMO2 chain to elucidate the interaction between them. In solution, the SIM domain was intrinsically disordered and the linkers of the tetra-SUMO2 were highly flexible. Individual SIMs of the RNF4-SIMs domains bind to SUMO2 in the groove between the beta2-strand and the alpha1-helix parallel to the beta2-strand. SIM2 and SIM3 bound to SUMO with a high affinity and together constituted the recognition module necessary for SUMO binding. SIM4 alone bound to SUMO with low affinity; however, its contribution to tetra-SUMO2 binding avidity is comparable with that of SIM3 when in the RNF4-SIMs domain. The SAXS data of the tetra-SUMO2-RNF4-SIMs domain complex indicate that it exists as an ordered structure. The HADDOCK model showed that the tandem RNF4-SIMs domain bound antiparallel to the tetra-SUMO2 chain orientation and wrapped around the SUMO protamers in a superhelical turn without imposing steric hindrance on either molecule.

Structural analysis of poly-SUMO chain recognition by the RNF4-SIMs domain.,Kung CC, Naik MT, Wang SH, Shih HM, Chang CC, Lin LY, Chen CL, Ma C, Chang CF, Huang TH Biochem J. 2014 Aug 15;462(1):53-65. doi: 10.1042/BJ20140521. PMID:24844634^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.