1JDR

Crystal Structure of a Proximal Domain Potassium Binding Variant of Cytochrome c Peroxidase

Summary for 1JDR

• Entry DOI: 10.2210/pdb1jdr/pdb
• Descriptor: Cytochrome c Peroxidase, POTASSIUM ION, PROTOPORPHYRIN IX CONTAINING FE, ... (4 entities in total)
• Functional Keywords: helical bundle protein, oxidoreductase
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Cellular location: Mitochondrion matrix: P00431
• Total number of polymer chains: 1
• Total formula weight: 34315.87

Authors

Bonagura, C.A.,Sundaramoorthy, M.,Bhaskar, B.,Poulos, T.L. (deposition date: 2001-06-14, release date: 2001-06-27, Last modification date: 2024-04-03)

Primary citation

Bonagura, C.A.,Sundaramoorthy, M.,Bhaskar, B.,Poulos, T.L.
The effects of an engineered cation site on the structure, activity, and EPR properties of cytochrome c peroxidase.
Biochemistry, 38:5538-5545, 1999

PubMed Abstract: Earlier work [Bonagura et al. (1996) Biochemistry 35, 6107] showed that the K+ site found in the proximal pocket of ascorbate peroxidase (APX) could be engineered into cytochrome c peroxidase (CCP). Binding of K+ at the engineered site results in a loss in activity and destabilization of the CCP compound I Trp191 cationic radical owing to long-range electrostatic effects. The engineered CCP mutant crystal structure has been refined to 1.5 A using data obtained at cryogenic temperatures which provides a more detailed basis for comparison with the naturally occurring K+ site in APX. The characteristic EPR signal associated with the Trp191 radical becomes progressively weaker as K+ is added, which correlates well with the loss in enzyme activity as [K+] is increased. These results coupled with stopped-flow studies support our earlier conclusions that the loss in activity and EPR signal is due to destabilization of the Trp191 cationic radical.

PubMed: 10220341
DOI: 10.1021/bi982996k

Experimental method

X-RAY DIFFRACTION (1.5 Å)