Extended Data Fig. 1: The prediction of an RNA-binding ___domain and highly disordered ___domain in GRP20.
a, The four prediction programs used for the RNA-binding prediction. The basic algorithms are shown in the table. b, The RNA binding propensity of GRP20 from catRAPID. The propensity ≥ 0.5 indicates potential RNA-binding ability, identifying the region with residue 92 to 115 as an RNA binding ___domain (highlighted by pink background). The overall interaction score of GRP20 is 0.54 (≥0.5), indicating that GRP20 is a putative RNA binding protein. c, The prediction of classification of the potential RNA-binding ___domain in GRP20 by catRAPID. The program divides potential RNA-binding proteins into three categories: classical, non-classical and putative according to propensity values79. The scores ≥ 0.5 reflects the propensity to be associated with one of the categories. The results indicate that the score of GRP20 is highest (0.72) for a non-classical RNA-binding protein and above threshold (0.59) for a putative RNA-binding protein, but not enough for a classic RNA-binding protein. d, RNA-binding propensity of GRP20 predicted by RNAbindPlus. The propensity ≥ 0.1 indicates potential RNA-binding residues in GRP20, in two regions: residue 20 to 30, and residue 96 to 116 (highlighted by pink). e, f, The prediction of core residues in GRP20 for RNA binding by DRNApred (e) and PPRlnt (f) programs. Each dot represents an amino acid. The amino acids with high probability for binding are indicated for the putative RNA-binding region (residue 92 to 116, highlighted by pink). The cutoff used in the two programs are 0.5 and −0.25, respectively. g, The GRP20 amino acid sequence, with the putative RNA-binding region (blue underlined) and key amino acids for RNA binding (Red letters: predicted by either predictor in e and f; Green letters: predicted by both predictors in e and f). h, The GRP20 gene structure with positions of two T-DNA insertion grp20 mutations (the triangles above gene structure). i, The relative expression of GRP20 in two grp20 alleles compared to WT by RT-qPCR. The expression level of GRP20 is normalized to WT being set as ‘1’. Two-sided Student’s t test. Data are presented as mean ± SE from three biological replicates. j, Vegetative growth between WT and two grp20 mutants. Some siliques are shorter, suggesting that the mutation of GRP20 affected fertility. Yellow arrows indicate short siliques. Bar = 10 cm.
