6533b858fe1ef96bd12b6456

RESEARCH PRODUCT

Heme Binding Constricts the Conformational Dynamics of the Cytochrome b559′ Heme Binding Cavity

Dirk SchneiderYasar AkdoganDariush HinderbergerVeerappan Anbazhagan

subject

Models MolecularHemeproteinCytochromeHeme bindingMolecular Sequence DataHemePlasma protein bindingBiochemistryProtein Structure SecondaryCofactorchemistry.chemical_compoundApoenzymesAmino Acid SequenceGlycophorinsHemebiologyCytochrome bCell MembraneElectron Spin Resonance SpectroscopyTemperaturePhotosystem II Protein ComplexSite-directed spin labelingCytochrome b GroupProtein Structure Tertiarychemistrybiology.proteinBiophysicsSpin LabelsPeptidesProtein Binding

description

Cytochrome b(559)' is a transmembrane protein formed by homodimerization of the 44-residue PsbF polypeptide and noncovalent binding of a heme cofactor. The PsbF polypeptide can dimerize in the absence and presence of heme. To monitor structural alterations associated with binding of heme to the apo-cytochrome, we analyzed the apo- and holo-cytochrome structure by electron paramagnetic resonance spectroscopy. Spin labeling of amino acids located close to the heme binding domain of the cytochrome revealed that the structure of the heme binding domain is unconstrained in the absence of heme. Heme binding restricts the conformational dynamics of the heme binding domain, resulting in the structurally more constricted holo-cytochrome structure.

yearjournalcountryeditionlanguage
2012-08-18Biochemistry
https://doi.org/10.1021/bi300489s