Related Experiment Video
Updated: Sep 23, 2026

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases
Published on: February 24, 2018
The 1.2 A structure of the human sulfite oxidase cytochrome b(5) domain
Michael J Rudolph1, Jean L Johnson, K V Rajagopalan
1Department of Pharmacological Sciences and Center for Structural Biology, State University of New York at Stony Brook, Stony Brook, New York 11794-5115, USA.
Abstract:
The molybdenum- and iron-containing enzyme sulfite oxidase catalyzes the physiologically vital oxidation of sulfite to sulfate. Sulfite oxidase contains three domains: an N-terminal cytochrome b(5) domain, a central domain harboring the molybdenum cofactor (Moco) and a C-terminal dimerization domain. Oxidation of the substrate sulfite is coupled to the transfer of two electrons to the molybdenum cofactor. Subsequently, these electrons are passed on, one at a time, to the b(5) heme of sulfite oxidase and from there to the soluble electron carrier cytochrome c. The crystal structure of the oxidized human sulfite oxidase cytochrome b(5) domain has been determined at 1.2 A resolution and has been refined to a crystallographic R factor of 0.107 (R(free) = 0.137). A comparison of this structure with other b(5)-type cytochromes reveals distinct structural features present in the sulfite oxidase b(5) domain which promote optimal electron transport between the Moco of sulfite oxidase and the heme of cytochrome c.
Related Concept Videos
Electron Transport Chain: Complex III and IV
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
ATP Synthase: Structure
Electron Transport Chains
The ETC is comprised of...
The Supercomplexes in the Crista Membrane
Structure and Nomenclature of Thiols and Sulfides
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
