1. (A) Schematic of the TGGT1_254250/TgPRELID gene, mRNA, and predicted protein.
(A) Schematic of the TGGT1_254250/TgPRELID gene, mRNA, and predicted protein. Intron-exon boundaries were predicted in ToxoDB and confirmed by direct sequencing of TGGT1_ transcript. Protein domain searches were done using Pfam, identifying a PRELI domain in amino acid residues 15 to 162. A putative transmembrane domain was also predicted using the Psipred and TMPred servers (residues 233 to 253). (B) Disopred3 analysis of TgPRELID polypeptide indicates a high probability of order in the first 150 amino acids (aa) that corresponds to the PRELI domain. Extensive patches of disorder are predicted C terminal to the PRELI domain. Some of these are also predicted to be protein binding (orange trace). (C) I-TASSER-predicted structure of TgPRELID PRELI domain (C score = 1.18), with identified mutations highlighted (IBETR, red; F0002R, blue). The electrostatic surface potential was calculated using APBS and mapped to the TgPRELID surface, in a gradient from negatively charged residues (red) to positively charged residues (blue). (D) Location of all TgPRELID mutations identified in ENU and CRISPR screens for F0002- and I-BET151-resistant mutants. All mutations associated with resistance to either F0002 or I-BET151 were located within the putative PRELI domain. In addition to F0002R mutants 1, 2, and 3, the three classes of CRISPR/CAS9-mediated resistance mutations are shown (CR1 and CR2 and that found in clones CRSOL1 and CRSOL2). All CRISPR-driven mutations showed no evidence for incorporation of the homology repair template containing the F105S mutation but instead resulted in either the deletion or the mutation of valine 133.
Victoria Jeffers et al. mSphere 2017; doi: /mSphere