title: Pseudomonas cytochrome c551 at 2.0 A resolution: enlargement of the cytochrome c family.
abstract: The structure of respiratory cytochrome c551 of Pseudomonas aeruginosa, with 82 amino acids, has been solved by x-ray analysis and refined to a crystallographic R factor of 16.2%. It has the same basic folding pattern and hydrophobic heme environment as cytochromes c, c2, and c550, except for a large deletion at the bottom of the heme crevice. This same "cytochrome fold" appears to be present in photosynthetic cytochromes c of green and purple sulfur bacteria, and algal cytochromes f, suggesting a common evolutionary origin for electron transport chains in photosynthesis and respiration.
mesh_terms: D001426:Bacterial Proteins; D005075:Biological Evolution; D003574:Cytochrome c Group; D003580:Cytochromes; D006418:Heme; D008958:Models, Molecular; D011487:Protein Conformation; D011550:Pseudomonas aeruginosa / Q000201:enzymology; D014961:X-Ray Diffraction
chemical_list: D001426:Bacterial Proteins; D003574:Cytochrome c Group; D003580:Cytochromes; D006418:Heme; C017167:cytochrome C(551)