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Published on: March 24, 2012
Structure of C73G putidaredoxin from Pseudomonas putida.
Natasha Smith1, Martin Mayhew, Marcia J Holden
1Biotechnology Division of the National Institute of Standards and Technology, Gaithersburg, MD 20899-8312, USA.
Summary
The crystal structure of the C73G mutant of putidaredoxin (Pdx) reveals key details about electron transfer. This ferredoxin structure provides insights into interactions with cytochrome CYP101 for camphor oxidation.
Area of Science:
- Biochemistry
- Structural Biology
- X-ray Crystallography
Background:
- Putidaredoxin (Pdx) is an Fe(2)S(2) ferredoxin essential for electron transfer.
- It supplies electrons to cytochrome CYP101 (p450cam) for camphor oxidation.
- Understanding Pdx structure is crucial for elucidating its function in enzymatic reactions.
Purpose of the Study:
- To determine the high-resolution crystal structure of the C73G mutant of putidaredoxin (Pdx).
- To compare the Pdx C73G structure with other Pdx mutants and solution structures.
- To identify conserved structural features important for electron transfer and protein interactions.
Main Methods:
- X-ray crystallography at 1.9 A resolution.
- Single-wavelength anomalous diffraction (SAD) using iron.
- Protein Data Bank deposition (accession code 1r7s).
Main Results:
- The C73G Pdx structure was solved, revealing three independent molecules in the asymmetric unit.
- The crystal structure is highly similar across independent molecules and to other Pdx mutants, differing from the solution structure.
- Conserved regions, including the cluster-binding loop and cytochrome-interaction sites, were identified.
Conclusions:
- The C73G Pdx crystal structure reveals conserved regions critical for electron transfer.
- Structural similarities across different Pdx forms suggest a stable conformation for functional interactions.
- Specific hydrogen bonding and conformational details (Cys45, Ala46) were observed in the crystal structure.
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