Conformational Rigidity and Protein Dynamics at Distinct Timescales Regulate PTP1B Activity and Allostery

Protein function originates from a cooperation of structural rigidity, dynamics at different timescales, and allostery. However, how these three pillars of protein function are integrated is still only poorly understood. Here we show how these pillars are connected in Protein Tyrosine Phosphatase 1B (PTP1B), a drug target for diabetes and cancer that catalyzes the dephosphorylation of numerous substrates in essential signaling pathways. By combining new experimental and computational data on WT-PTP1B and ≥10 PTP1B variants in multiple states, we discovered a fundamental and evolutionarily conserved CH/π switch that is critical for positioning the catalytically important WPD loop. Furthermore, our data show that PTP1B uses conformational and dynamic allostery to regulate its activity. This shows that both conformational rigidity and dynamics are essential for controlling protein activity. This connection between rigidity and dynamics at different timescales is likely a hallmark of all enzyme function. [Display omitted] •Distinct dynamic timescales underlie catalysis versus allosteric control in PTP1B•Fast and slow timescale motions are uncoupled in PTP1B•The rigid CH/π switch is critical for the opening and closing of the WPD loop•Fast timescale motions, via helix α7, allow for PTP1B allosteric control By integrating NMR, crystallography, and enzymatic studies of PTP1B and its variants in multiple states, Choy et al. reveal that in PTP1B, rigidity and slow timescale motions are required for catalysis, while fast timescale motions allow for its allosteric control