1MDV

KEY ROLE OF PHENYLALANINE 20 IN CYTOCHROME C3: STRUCTURE, STABILITY AND FUNCTION STUDIES

Summary for 1MDV

• Entry DOI: 10.2210/pdb1mdv/pdb
• Descriptor: CYTOCHROME C3, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• Functional Keywords: mutant cytochrome c3, desulfovibrio vulgaris hildenborough, electron transport
• Biological source: Desulfovibrio vulgaris subsp. vulgaris str. Hildenborough
• Cellular location: Periplasm: P00131
• Total number of polymer chains: 2
• Total formula weight: 28238.79

Authors

Dolla, A.,Arnoux, P.,Protasevich, I.,Lobachov, V.,Brugna, M.,Guidici-Orticoni, M.T.,Haser, R.,Czjzek, M.,Makarov, A.,Brushi, M. (deposition date: 1998-09-08, release date: 1999-05-04, Last modification date: 2024-10-23)

Primary citation

Dolla, A.,Arnoux, P.,Protasevich, I.,Lobachov, V.,Brugna, M.,Giudici-Orticoni, M.T.,Haser, R.,Czjzek, M.,Makarov, A.,Bruschi, M.
Key role of phenylalanine 20 in cytochrome c3: structure, stability, and function studies.
Biochemistry, 38:33-41, 1999

PubMed Abstract: Aromatic residues in c-type cytochromes might have an important function in the folding and/or electron transferring properties of the molecule. In the tetraheme cytochrome c3 (Mr 13 000) from Desulfovibrio vulgaris Hildenborough, Phe20, is located between heme 1 and heme 3 with its aromatic ring close and almost parallel to the ring plane of heme 1. We replaced this residue by a nonaromatic hydrophobe residue, leucine, and analyzed the effects in terms of functional, structural, and physicochemical properties. While the F20L replacement did not have any strong effects on the heme region stability, a decrease of the thermostability of the whole molecule was observed. In the same way, the four macroscopic redox potentials were affected by the mutation as well as the flexibility of the surface loop around heme 4. The F20L replacement itself and/or this structural modification might be responsible for the loss of the intermolecular cooperativity between F20L cytochrome c3 molecules.

PubMed: 9890880
DOI: 10.1021/bi981593h

Experimental method

X-RAY DIFFRACTION (2.3 Å)