Fig. 1: APC3 binds nucleosome acidic patch through HMGN-like nucleosome binding motif.
From: APC/C-mediated ubiquitylation of extranucleosomal histone complexes lacking canonical degrons
a Electrostatic surface of nucleosome (PDB 3AFA), left, and zoomed view of acidic patch showing residues mutated in acidic patch interaction screen, right. b Profile plots of APC/C subunits and HMGN1 for triplicate wild-type and mutant nucleosome affinity proteomics experiments (data from41). Individual quantitated peptides shown in grey and weighted averages in red or blue. ∆AP: H2A E61A, E64S, N68A, D72S, N89A, D90A, E91S. Additional profile plots shown in Supplementary Fig. 1. c Pulldowns from HEK293T nuclear lysates using reconstituted, wild-type or mutant biotinylated nucleosomes followed by western blot for APC2, APC5 or APC/C coactivator, CDC20. Pulldown-westerns performed one time. d Schematic of nucleosome label transfer crosslinking experiment with H2A E91C linked to Mts-Atf-Biotin reagent, left. Photocrosslinking followed by TCEP addition, allows transfer of biotin to crosslinked protein. Simultaneous blot for biotin and APC3 consistent with photocrosslinking to APC3. Photocrosslinking performed two times with equivalent results. e Sequence alignment of proposed APC3 nucleosome-binding loop and HMGN proteins showing partial conservation of HMGN nucleosome binding motif. Source data are provided as a Source Data file.
