1u6g
From Proteopedia
Crystal Structure of The Cand1-Cul1-Roc1 Complex
Overview
The SCF ubiquitin ligase complex regulates diverse cellular functions by ubiquitinating numerous protein substrates. Cand1, a 120 kDa HEAT repeat protein, forms a tight complex with the Cul1-Roc1 SCF catalytic core, inhibiting the assembly of the multisubunit E3 complex. The crystal structure of the Cand1-Cul1-Roc1 complex shows that Cand1 adopts a highly sinuous superhelical structure, clamping around the elongated SCF scaffold protein Cul1. At one end, a Cand1 beta hairpin protrusion partially occupies the adaptor binding site on Cul1, inhibiting its interactions with the Skp1 adaptor and the substrate-recruiting F box protein subunits. At the other end, two Cand1 HEAT repeats pack against a conserved Cul1 surface cleft and bury a Cul1 lysine residue, whose modification by the ubiquitin-like protein, Nedd8, is able to block Cand1-Cul1 association. Together with biochemical evidence, these structural results elucidate the mechanisms by which Cand1 and Nedd8 regulate the assembly-disassembly cycles of SCF and other cullin-dependent E3 complexes.
About this Structure
1U6G is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Structure of the Cand1-Cul1-Roc1 complex reveals regulatory mechanisms for the assembly of the multisubunit cullin-dependent ubiquitin ligases., Goldenberg SJ, Cascio TC, Shumway SD, Garbutt KC, Liu J, Xiong Y, Zheng N, Cell. 2004 Nov 12;119(4):517-28. PMID:15537541 Page seeded by OCA on Sat May 3 10:49:00 2008
