3E2N

Engineering ascorbate peroxidase activity into cytochrome c peroxidase

Summary for 3E2N

• Entry DOI: 10.2210/pdb3e2n/pdb
• Related: 1DSG 1DSO 1ZBY 2V23 3E2O 5CCP
• Descriptor: Cytochrome c peroxidase, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• Functional Keywords: cytochrome c peroxidase (ccp), ascorbate peroxidase (apx), oxidoreductase
• Biological source: Saccharomyces cerevisiae; More
• Total number of polymer chains: 1
• Total formula weight: 33218.96

Authors

Poulos, T.L.,Meharenna, Y.T.,Oertel, P. (deposition date: 2008-08-05, release date: 2008-10-21, Last modification date: 2023-08-30)

Primary citation

Meharenna, Y.T.,Oertel, P.,Bhaskar, B.,Poulos, T.L.
Engineering ascorbate peroxidase activity into cytochrome c peroxidase.
Biochemistry, 47:10324-10332, 2008

PubMed Abstract: Cytochrome c peroxidase (CCP) and ascorbate peroxidase (APX) have very similar structures, and yet neither CCP nor APX exhibits each other's activities with respect to reducing substrates. APX has a unique substrate binding site near the heme propionates where ascorbate H-bonds with a surface Arg and one heme propionate (Sharp et al. (2003) Nat. Struct. Biol. 10, 303-307). The corresponding region in CCP has a much longer surface loop, and the critical Arg residue that is required for ascorbate binding in APX is Asn in CCP. In order to convert CCP into an APX, the ascorbate-binding loop and critical arginine were engineered into CCP to give the CCP2APX mutant. The mutant crystal structure shows that the engineered site is nearly identical to that found in APX. While wild-type CCP shows no APX activity, CCP2APX catalyzes the peroxidation of ascorbate at a rate of approximately 12 min (-1), indicating that the engineered ascorbate-binding loop can bind ascorbate.

PubMed: 18771292
DOI: 10.1021/bi8007565

Experimental method

X-RAY DIFFRACTION (1.3 Å)