A Broad range of conformations contribute to the solution ensemble of the essential splicing factor U2AF(65).
U2AF(65) is essential for pre-mRNA splicing in most eukaryotes. Two consecutive RNA recognition motifs (RRM) of U2AF(65) recognize a polypyrimidine tract at the 3' splice site. Here, we use small-angle X-ray scattering to demonstrate that the tandem U2AF(65) RRMs exhibit a broad range of conformations in the solution ensemble. The majority of U2AF(65) conformations exhibit few contacts between the RRMs, such as observed in the crystal structure. A subpopulation adopts tight inter-RRM contacts, such as independently reported based on paramagnetic relaxation enhancements. These complementary structural methods demonstrate that diverse splice sites have the opportunity to select compact or extended inter-RRM proximities from the U2AF(65) conformational pool.
Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
Jermaine L
JL
Jenkins
Kholiswa M
KM
Laird
Clara L
CL
Kielkopf
D018360:Crystallography, X-Ray; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012326:RNA Splicing / Q000502:physiology; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000378:metabolism; D012996:Solutions; D000072668:Splicing Factor U2AF
D009687:Nuclear Proteins; D012261:Ribonucleoproteins; D012996:Solutions; D000072668:Splicing Factor U2AF; C000607494:U2AF2 protein, human