Fig. 2.
SPR shows mStau2 binding to SRS2 + 5 RNA and SRS* RNA. a mStau2 dsRBD 1–2, and b mStau2 dsRBD 3–4 binding to surface-coupled SRS2 + 5 and SRS* RNAs. The tandem domains dsRBD 1–2 and dsRBD 3–4 bind transiently with fast kinetics. The steady-state binding curves do not saturate up to 1 µM protein concentration but can be described by a two-site binding fit with KD1 of 18 nM and 130 nM, respectively, for SRS2 + 5 and KD1 of 9 nM and 25 nM, respectively, for SRS*. c mStau2 dsRBD 1–4 binding to surface-coupled SRS2 + 5 and SRS* RNAs is stable with slower kinetics. The steady-state binding curve saturates at approximately 1 µM and is described by a Hill fit with an apparent overall KD of 357 nM and a Hill coefficient n = 1.7 for SRS2 + 5 and an apparent overall KD of 330 nM and a Hill coefficient n = 1.8 for SRS*, indicating positive cooperative binding. d SRS2 + 5 and SRS* bind to surface-coupled mStau2 FL stably and with high affinity. The steady-state binding curves can be described by a two-site binding fit with KD1 of 1.3 nM and 10.6 nM and KD2 of 185 nM and 195 nM, respectively. ± indicates standard deviation. Source data are provided as a Source Data file