Identification of Bvh . A. Alignment of Bvh protein with human (NP_077726) and mouse (NP_001139357). Black boxes indicate positions at which the residues are identical and grey boxes highlight residues that are similar. Functional domains and motifs are indicated in underline and pane, respectively. B. The three-dimensional structure of the helicase core domains of the Bvh protein. The conserved sequence motifs within these domains are shown, with colour coding that corresponds to the primary function of the domain. Red indicate Domain 1 (DEADc domain). Purple indicate Domain 2 (HELICc domain). Green indicate unconcerved region. Yellow indicate ATP binding site. Blue indicate RNA binding site. Pink indicate communication between ATP-binding and RNA-binding sites. C. The phylogenetic relationship of bovine with other mammals and their divergence time. Mammal groups in blue and bird groups in red. Drawings are based on Graves and Westerman , and Xu et al .