1jdr
Crystal Structure of a Proximal Domain Potassium Binding Variant of Cytochrome c Peroxidase
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| , resolution 1.5Å | |||||||
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| Ligands: | and | ||||||
| Gene: | OPBYC (Saccharomyces cerevisiae) | ||||||
| Activity: | Cytochrome-c peroxidase, with EC number 1.11.1.5 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
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.
About this StructureAbout this Structure
1JDR is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
ReferenceReference
The effects of an engineered cation site on the structure, activity, and EPR properties of cytochrome c peroxidase., Bonagura CA, Sundaramoorthy M, Bhaskar B, Poulos TL, Biochemistry. 1999 Apr 27;38(17):5538-45. PMID:10220341
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