Key role of phenylalanine 20 in cytochrome c3: structure, stability, and function studies.


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. Study holds ProTherm entries: 16307, 16308 Extra Details: The partial molar heat capacity at 20 C is 3.8 kcal/K mol. cytochrome c3, mutagenesis, heme region stability, phenylalanine 20

Submission Details

ID: aPMGCqvk3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:47 p.m.

Version: 1

Publication Details
Dolla A;Arnoux P;Protasevich I;Lobachov V;Brugna M;Giudici-Orticoni MT;Haser R;Czjzek M;Makarov A;Bruschi M,Biochemistry (1999) Key role of phenylalanine 20 in cytochrome c3: structure, stability, and function studies. PMID:9890880
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Cytochrome c3 P00131 CYC3_DESVH
100.0 High-molecular-weight cytochrome c P24092 HMWC_DESVH