9QDT

Cytochrome c peroxidase YhjA

Summary for 9QDT

• Entry DOI: 10.2210/pdb9qdt/pdb
• Descriptor: Probable cytochrome c peroxidase, HEME C, PROTOPORPHYRIN IX CONTAINING FE, ... (8 entities in total)
• Functional Keywords: cytochrome c, peroxidase, multiheme protein, oxidoreductase
• Biological source: Escherichia coli K-12
• Total number of polymer chains: 1
• Total formula weight: 48715.81

Authors

Einsle, O.,Wuest, A. (deposition date: 2025-03-06, release date: 2025-07-30, Last modification date: 2025-08-13)

Primary citation

Hewitt, P.,Seidel, J.,Wust, A.,Smith, M.,Maiocco, S.J.,Shternberg, S.,Hoffmann, M.,Spatzal, T.,Gerhardt, S.,Einsle, O.,Elliott, S.J.
Escherichia coli Triheme Enzyme YhjA: Structure and Reactivity.
Biochemistry, 64:3322-3332, 2025

PubMed Abstract: It has been recently realized that some Gram-negative organisms such as produce a multiheme cytochrome to serve as a quinol peroxidase that couples electrons from the quinol pool directly to HO. The version of this enzyme, termed YhjA, has been predicted to be a member of the bacterial cytochrome peroxidase (bCCP) superfamily, where a novel N-terminal single-heme binding domain is fused to the canonical bCCP diheme domain found widely in Gram-negative bacteria. Here, we present an X-ray crystal structure of YhjA, revealing the triheme architecture that nature has employed to couple the quinol pool to the reduction of HO. We also show kinetic, spectroscopic, and electrochemical data that detail the differences between the three hemes that are observed in the structure, where two of the heme irons are both six-coordinate, ligated by Met and His residues, and the third peroxidatic heme is found to be five-coordinate. Electrocatalytic voltammetry of YhjA illustrates how the high-potential hemes serve as relays to the peroxidatic active site. Together, these data suggest a model of the catalytic chemistry of YhjA, illustrating how this member of the bCCP family may react with substrates and engage in multielectron redox reactions.

PubMed: 40669070
DOI: 10.1021/acs.biochem.5c00202

Experimental method

X-RAY DIFFRACTION (2.572 Å)