FIG 2.

Accelerated evolution of the C-terminal polybasic motif of primate GBP1 and GBP2. (A) Species tree of simian primates used for phylogenetic analyses. Species in black were included in both the GBP1 and GBP2 data sets. Asterisks (*) indicate species that were included in GBP1 analysis alone. Crosshatch symbols (#) indicate species that were included in GBP2 analysis alone. (B) Sites in GBP1 (PDB ID 1DG3) that exhibited a statistically significant elevation in dN/dS ratio, indicative of repeated positive selection. Site numbers correspond to human GBP1 and were identified using at least four separate inference methods in the PAML and HyPhy software packages. (C) Sites in GBP2 that displayed a statistically significant elevation in dN/dS ratio, indicative of repeated positive selection. Site numbers correspond to human GBP2 and were determined using at least four separate inference methods as described for panel B. A three-dimensional predicted structure of human GBP2 was generated using the I-Tasser modeling program based on human GBP1.