Journal: Nature Communications
Article Title: An extended U2AF 65 –RNA-binding domain recognizes the 3′ splice site signal
doi: 10.1038/ncomms10950
Figure Lengend Snippet: ( a ) Contacts of the U2AF 65 inter-RRM linker with the RRMs. A semi-transparent space-filling surface is shown for the RRM1 (green) and RRM2 (light blue). Residues V249, V250, V254 (yellow) are mutated to V249G/V250G/V254G in the 3Gly mutant; residues S251, T252, V253, P255 (red) along with V254 are mutated to S251G/T252G/V253G/V254G/P255G in the 5Gly mutant or to S251N/T252L/V253A/V254L/P255A in the NLALA mutant; residues M144, L235, M238, V244, V246 (orange) along with V249, V250, S251, T252, V253, V254, P255 are mutated to M144G/L235G/M238G/V244G/V246G/V249G/ V250G/S251G/T252G/V253G/V254G/P255G in the 12Gly mutant. Other linker residues are coloured either dark blue for new residues in the U2AF 65 1,2L structure or light blue for the remaining inter-RRM residues. The central panel shows an overall view with stick diagrams for mutated residues; boxed regions are expanded to show the C-terminal (bottom left) and central linker regions (top) at the inter-RRM interfaces, and N-terminal linker region contacts with RRM1 (bottom right). ( b ) Bar graph of apparent equilibrium affinities ( K A ) for the AdML Py tract (5′-CCCUUUUUUUUCC-3′) of the wild-type (blue) U2AF 65 1,2L protein compared with mutations of the residues shown in a : 3Gly (yellow), 5Gly (red), NLALA (hatched red), 12Gly (orange) and the linker deletions dU2AF 65 1,2 in the minimal RRM1–RRM2 region (residues 148–237, 258–336) or dU2AF 65 1,2L (residues 141–237, 258–342). The apparent equilibrium dissociation constants ( K D ) of the U2AF 65 1,2L mutant proteins are: wild type (WT), 35±6 nM; 3Gly, 47±4 nM; 5Gly, 61±3 nM; 12Gly, 88±21 nM; NLALA, 45±3 nM; dU2AF 65 1,2L, 123±5 nM; dU2AF 65 1,2, 5000±100 nM; 3Mut, 5630±70 nM. The average K A and s.e.m. for three independent titrations are plotted. The P values from two-tailed unpaired t -tests with Welch's correction are indicated as follows: ** P <0.01; * P <0.05; NS, not significant, P >0.05. The fitted fluorescence anisotropy RNA-binding curves are shown in . ( c ) Close view of the U2AF 65 RRM1/RRM2 interface following a two-fold rotation about the x -axis relative to a .
Article Snippet: The U2AF 65 1,2L FRET construct used for smFRET comprises the six histidine and T7 tags from the pET28a vector (Merck), a GGGS linker and U2AF 65 residues 113–343.
Techniques: Mutagenesis, Two Tailed Test, Fluorescence, RNA Binding Assay