2JTI

Solution structure of the yeast iso-1-cytochrome c (T12A) : yeast cytochrome c peroxidase complex

Summary for 2JTI

• Entry DOI: 10.2210/pdb2jti/pdb
• Related: 1ycc 1zby 2gb8 2pcc
• Descriptor: Cytochrome c peroxidase, mitochondrial, Cytochrome c iso-1, PROTOPORPHYRIN IX CONTAINING FE, ... (4 entities in total)
• Functional Keywords: protein/protein, heme, hydrogen peroxide, iron, metal-binding, mitochondrion, oxidoreductase, peroxidase, transit peptide, electron transport, methylation, respiratory chain, transport, oxidoreductase-electron transport complex, oxidoreductase/electron transport
• Biological source: Saccharomyces cerevisiae (yeast); More
• Cellular location: Mitochondrion matrix: P00431; Mitochondrion intermembrane space: P00044
• Total number of polymer chains: 2
• Total formula weight: 46804.06

Authors

Ubbink, M.,Volkov, A.N. (deposition date: 2007-08-01, release date: 2008-07-22, Last modification date: 2024-10-30)

Primary citation

Volkov, A.N.,Bashir, Q.,Worrall, J.A.,Ullmann, G.M.,Ubbink, M.
Shifting the equilibrium between the encounter state and the specific form of a protein complex by interfacial point mutations.
J.Am.Chem.Soc., 132:11487-11495, 2010

PubMed Abstract: Recent experimental studies have confirmed a long-held view that protein complex formation proceeds via a short-lived encounter state. The population of this transient intermediate, stabilized mainly by long-range electrostatic interactions, varies among different complexes. Here we show that the occupancy of the encounter state can be modulated across a broad range by single point mutations of interfacial residues. Using a combination of Monte Carlo simulations and paramagnetic relaxation enhancement NMR spectroscopy, we illustrate that it is possible to both enhance and diminish the binding specificity in an electron transfer complex of yeast cytochrome c (Cc) and cytochrome c peroxidase. The Cc T12A mutation decreases the population of the encounter to 10% as compared with 30% in the wild-type complex. More dramatically, the Cc R13A substitution reverses the relative occupancies of the stereospecific and the encounter forms, with the latter now being the dominant species with the population of 80%. This finding indicates that the encounter state can make a large contribution to the stability of a protein complex. Also, it appears that by adjusting the amount of the encounter through a judicious choice of point mutations, we can remodel the energy landscape of a protein complex and tune its binding specificity.

PubMed: 20672804
DOI: 10.1021/ja100867c

Experimental method

SOLUTION NMR