Dantas, JM, Morgado L, Pokkuluri PR, Turner DL, Salgueiro CA.  2013.  Solution structure of a mutant of the triheme cytochrome PpcA from Geobacter sulfurreducens sheds light on the role of the conserved aromatic residue F15. Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1827(4):484-492.