These alignments indicate that inCfl.aurantiacusand
Rfl castenholzii the His residue that serves as an axial ligand to BB
(residue M180 in B. viridis and Rb. capsulatus, and M182 in Rb.
sphaeroides) is leucine and isoleucine, respectively, and the His at
L153, which serves as the ligand to BA, is preserved [8,9]. Furthermore,
The L- and M-subunits ofRfl. castenholziishow relatively high homology