Duck RIG-I CARD domains are ubiquitinated at K167 and K193.

<p>A. Coomassie stained gel showing the different ubiquitinated forms of the duck RIG-I CARD domains. B. MaxEnt3 deconvoluted MS/MS spectra of a peptide bearing the typical diglycine signal for ubiquitination at Lys 193, showing the singly-charged forms of the B and Y ions detected. C. Three-dimensional detail of duck RIG-I structure in the region of Q170 (red), corresponding to human K172, and the closest lysine, K167 (blue) (PDB code:4a2w) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0086968#pone.0086968-Kowalinski2" target="_blank">[31]</a>. Figure was created using Protean 3D from DNA Lasergene 9. D. MaxEnt3 deconvoluted MS/MS spectra of a peptide showing the ubiquitination signal for K167. E. GST pulldown of duck CARD domains from cells co-transfected with HA-ubiquitin, or HA-ubiquitin-K0 (all lysines mutated) or HA-ubiquitin K63 (only lysine 63 intact). Band 2 in the GST pulldown is a doublet and the lower band is missing in the absence of K63-linked ubiquitin chains. F. MaxEnt3 deconvoluted MS/MS spectra of a peptide of ubiquitin recovered from band 2 showing the diglycine signal at Lys 63, indicating the presence of Lys 63-linked polyubiquitin.</p>