Figure 2

Computational assessment of the predicted activation states of AtPSKR1 kinase and GC catalytic centers. AtPSKR1-kinase domain (Phe⁷³⁴ – Val¹⁰⁰⁸) was modeled against the AvrPtoB-BAK1 complex (PDB entry: 3TL8) (A) and against the bacteria GC Cya2 (PDB entry: 2W01) (B) using the Modeller (ver. 9.10) software [14], and GTP docking experiments performed using AutoDock Vina (ver. 1.1.2) [15]. When AtPSKR1 assumes the kinase activation state (A), the GC catalytic center is partially covered by a nine amino acid long ‘latch’ that may be loosened by a molecular switch (e.g. Ca²⁺) or by forming homo- or hetero-dimers. When AtPSKR1 assumes a GC configuration (B), the GC catalytic center is completely exposed and assessable to GTP. In addition, automated docking experiments suggest feasible GTP docking. The GC catalytic center is in yellow, functionally assigned residues in the GC motif are in cyan, amino acids implicated in metal binding are in green, the ATP-binding site is in orange and the nine amino acid long ‘latch’ partially covering the GC catalytic center is in magenta.