Comparative Evolutionary Genomics of Androgen-Binding Protein Genes

Site-specific K_A/K_S analysis of Abpa-like and Abpbg-like genes mapped to the tertiary structure of cat Fel dI. ω⁺ codons that are predicted to be under positive selection for mouse paralogs are mapped to a ribbon representation of the tertiary structure of feline major allergen Fel dI (PDB 1POU; Kaiser et al. 2003). (A) Ribbon diagram of the Fel dI dimer. Side chains of mapped predicted ω⁺ sites are highlighted in red. A single ligand molecule (2-methyl-2,4-pentanediol) present in the crystal structure is colored orange. (B) A representation of the molecular surface of the Fel dI chain 1 and 2 heterodimer. Mapped ABPα ω⁺ sites are shown in blue, and ABPβγ ω⁺ sites are shown in red. (C) Mapped ω⁺ sites predicted for the Abpa-like mouse paralogs. (D) Mapped ω⁺ sites predicted for the Abpbg-like mouse paralogs. (E) Prediction of the ABPβγ terminal extension and the mapped location of identified ω⁺ sites. The ABPβγ teminal extension is predicted to form a helical structure of ∼24 residues and is shown to scale. Swiss-PDBviewer (http://www.expasy.org/spdbv/; Guex et al. 1999) was used for all structural manipulations, and POVRAY (http://www.povray.org) was used to generate images.