(A) HDX-MS identified regions protected from HDX in the
RAPTOR/RagA-Q66LGTP/RagCT90NGDP complex. Decreases in
HDX (blue) of RAPTOR upon RagA/C binding are depicted on the RAPTOR structure
(from PDB ID: 6BCX).
(B, C) Differences in HDX for RagA-Q66LGTP
(B) and RagC-T90NGDP (C) upon RAPTOR
binding for all the peptides at 0.3 s in D2O. Decreases in HDX are
depicted in shades of blue, and increases are in shades of red.
(D) The crystal structure of
RagA-Q66LGTP/RagC(34-399)-T90NGDP, highlighting the
ordered switches in RagAGTP compared with disordered switches in
RagC-T90NGDP oncogenic mutant.
(E) The conserved G-motifs of RagA-Q66LGTP that make up
the nucleotide binding pocket.
(F) The 2mFo-DFc map (contoured at 1.2σ) for the GTP of RagA
and the GDP of RagC together with the putative H-bonds that they make to the
G-motifs. These are much more extensive for GTP than for GDP.