Fig. 4: Structural proteomics using an MS-cleavable crosslinker reveals TIR1·IAA7 and TIR1·IAA12 interaction interfaces. | Nature Communications

Fig. 4: Structural proteomics using an MS-cleavable crosslinker reveals TIR1·IAA7 and TIR1·IAA12 interaction interfaces.

From: Flexibility of intrinsically disordered degrons in AUX/IAA proteins reinforces auxin co-receptor assemblies

Fig. 4

a Workflow for the cross-linking coupled to mass spectrometry (XL-MS) approach. Recombinant oligomerization-deficient IAA7 (orange) and IAA12 (aquamarine) proteins, and ASK1·TIR1 (gray and light pink, respectively) were incubated with the DSBU crosslinker, and samples were analyzed using LC/MS2. Crosslinked peptides were identified using the MeroX software. b Interaction interfaces (blue) on TIR1 converge in two distinct patches around LRR4–7 (cluster 1) or LRR17–18 (cluster 2) revealing AUX/IAAs adopt an extended fold when in complex with TIR1. c Circular depiction of inter-protein (TIR1·AUX/IAAs) (blue) and intra-protein (red) crosslinks (XLs) along IAA7 (orange), IAA12 (aquamarine), TIR1 (light pink) and ASK1 (gray) protein sequence. XLs were identified in at least 2/3 or 3/4 independent experiments (dashed: 2/3 and 3/4; solid lines: 3/3 and 4/4). Specific XLs within TIR1 and between TIR1 and ASK1 (green) are in agreement with the crystal structure (PDB: 2P1Q [http://www.rcsb.org/structure/2P1Q]). Known motifs and protein domains are displayed.

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