FIG. 2.

Alignment of the amino acid sequences of β (A), γ (B), and ɛ (C) subunits of Rhodobacter capsulatus (rc), E. coli (ec), and bovine heart mitochondria (bt). Asterisks indicate identical residues, dots indicate conservative substitutions, E’s and double underlines indicate β strands, and H’s and black boxes indicate α helices. The secondary structures of β and γ subunits have been obtained from the atomic coordinates of bovine heart mitochondria F₁ (1), and the secondary structural elements of the ɛ subunit have been obtained from nuclear magnetic resonance models of E. coli (33).