FIGURE 1.
3′-processing of U6 snRNA alters its recognition by S. pombe Lsm2–8. (A) Processing of U6 by Usb1 leaves a 3′ cyclic phosphate group on U6, denoted as “>p.” (B) In vitro fluorescence polarization binding assays show that S. pombe Lsm2–8 preferentially binds RNA that has been processed by Usb1. All binding curves and Kd determinations in this work were performed with a restrained Hill coefficient of 1. For reference, the nonrestrained Hill coefficients, which are close to 1, are shown in the figure.