title: Engineering specificity in a dynamic protein complex with a single conserved mutation.
abstract: It has been demonstrated that the complex of yeast cytochrome c (Cc) and cytochrome c peroxidase (CcP) exists as a delicate equilibrium of a specific, active state and the non-specific, dynamic encounter state. An ortholog of yeast Cc, horse Cc, binds CcP but forms a much more dynamic complex, as demonstrated by NMR spectroscopy. A single conservative mutation of lysine 13 to arginine reduces the dynamics and enhances the specificity. The crystal structure of the stereospecific complex resembles the yeast Cc-CcP complex. In contrast, the K13A mutation increases the dynamic nature of the complex with CcP, showing that specificity in a redox protein complex can depend on the interactions of a single side chain in the binding interface.
authors.affiliation: Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, The Netherlands.
authors.forename: Qamar
authors.initials: Q
authors.lastname: Bashir
authors.forename: Elisabeth M
authors.initials: EM
authors.lastname: Meulenbroek
authors.forename: Navraj S
authors.initials: NS
authors.lastname: Pannu
authors.forename: Marcellus
authors.initials: M
authors.lastname: Ubbink
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D018360:Crystallography, X-Ray; D003578:Cytochrome-c Peroxidase / Q000737:chemistry* / Q000378:metabolism; D045304:Cytochromes c / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006736:Horses; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D019906:Nuclear Magnetic Resonance, Biomolecular; D017354:Point Mutation; D011485:Protein Binding; D011487:Protein Conformation; D025941:Protein Interaction Mapping; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013113:Spin Labels; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D013113:Spin Labels; D045304:Cytochromes c; D003578:Cytochrome-c Peroxidase
keywords: cytochrome c; cytochrome c peroxidase; electron transport; nuclear magnetic resonance; protein-ligand interactions; specificity; transient complex