Unless stated otherwise, all analysis of all conventional and enhanced sampling molecular dynamics simulations was performed using CPPTRAJ. Hydrogen bonds were defined as formed if the donor-acceptor distance was ≤3.0 Å and the donor-hydrogen-acceptor angle was within 180 ± 45°. Principal component analysis (PCA) was performed by first RMS fitting to a whole protein Ca carbon atoms and then performing PCA on the Cα carbon atoms of loops 1, 5 and 6, as well as loop 1 for HisA loop 1 elongated systems analysis. Other analyses were performed as described in the Supporting Information.