Structure and stability effects of the mutation of glycine 34 to serine in Rhodobacter capsulatus cytochrome c(2).


Abstract

Gly 34 and the adjacent Pro 35 of Rhodobacter capsulatus cytochrome c(2) (or Gly 29 and Pro 30 in vertebrate cytochrome c) are highly conserved side chains among the class I c-type cytochromes. The mutation of Gly 34 to Ser in Rb. capsulatus cytochrome c(2) has been characterized in terms of physicochemical properties and NMR in both redox states. A comparison of the wild-type cytochrome c(2), the G34S mutation, and the P35A mutation is presented in the context of differences in chemical shifts, the differences in NOE patterns, and structural changes resulting from oxidation of the reduced cytochrome. G34S is substantially destabilized relative to wild-type (2.2 kcal/mol in the oxidized state) but similarly destabilized relative to P35A. Nevertheless, differences in terms of the impact of the mutations on specific structural regions are found when comparing G34S and P35A. Although available data indicates that the overall secondary structure of G34S and wild-type cytochrome c(2) are similar, a number of both perturbations of hydrogen bond networks and interactions with internal waters are found. Thus, the impact of the mutation at position 35 is propagated throughout the cytochrome but with alterations at defined sites within the molecule. Interestingly, we find that the substitution of serine at position 34 results in a perturbation of the heme beta meso and the methyl-5 protons. This suggests that the hydroxyl and beta carbon are positioned away from the solvent and toward the heme. This has the consequence of preferentially stabilizing the oxidized state in G34S, thus, altering hydrogen bond networks which involve the heme propionate, internal waters, and key amino acid side chains. The results presented provide important new insights into the stability and solution structure of the cytochrome c(2). Study holds ProTherm entries: 7959, 7960, 7961 Extra Details: physicochemical properties; chemical shifts; secondary,structure; hydrogen bond networks

Submission Details

ID: UHZZNw3G4

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:35 p.m.

Version: 1

Publication Details
Zhao D;Hutton HM;Meyer TE;Walker FA;MacKenzie NE;Cusanovich MA,Biochemistry (2000) Structure and stability effects of the mutation of glycine 34 to serine in Rhodobacter capsulatus cytochrome c(2). PMID:10747794
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 PDB Entries

Structure ID Release Date Resolution Structure Title
1C2N 1999-03-23 CYTOCHROME C2, NMR, 20 STRUCTURES
1VYD 2004-06-17 2.3 Crystal structure of cytochrome C2 mutant G95E
1C2R 1992-01-15 2.5 MOLECULAR STRUCTURE OF CYTOCHROME C2 ISOLATED FROM RHODOBACTER CAPSULATUS DETERMINED AT 2.5 ANGSTROMS RESOLUTION

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Cytochrome c2 P00094 CYC2_RHOCB