This project made use of time on ARCHER granted via the UK High-End Computing Consortium for Biomolecular Simulation, HECBioSim (http://hecbiosim.ac.uk) and the CAMP HPC cluster of The Francis Crick Institute. The authors acknowledge use of the research computing facility at King's College London, Rosalind (https://rosalind.kcl.ac.uk). Supported by the Ministry for Innovation and Technology and the National Research, Development and Innovation Fund of Hungary (K135231, NKP-2018-1.2.1-NKP-2018-00005, TKP2021-EGA-02, to B.G.V. and K.N.).

Additional material for Berta et al. J. Am. Chem. Soc. 2023, 145, 37, 20302–20310 Paths: minimised structures corresponding to the the GTP hydrolysis mechanism. MD setup: equilibriated inputs for classical MD simulations for WT and mutant systems in CHARMM/NAMD format, set up for the charmm36m FF. NBO: outputs for Natrual Bonding Orbitals analysis carried out for TS and RS structures. GAP mutants: optimised TS and RS structures of the most promising designed GAP mutants.