Fig. 2. Representative views of the U2AF1 interactions with each nucleotide at the 3′ splice site.

a Interaction of U2AF1 with adenine at −2 position. b Interaction of U2AF1 with guanine at −1 position and (c) with guanine at +1 position structures. In U2AF1, ZF1, ZF2, and RNA are colored as in Fig. 1b.