Related Experiment Video
Updated: Jul 8, 2026

Visualization of ATP Synthase Dimers in Mitochondria by Electron Cryo-tomography
Published on: September 14, 2014
Structure of alpha-glycerophosphate oxidase from Streptococcus sp.: a template for the mitochondrial
Timothy Colussi1, Derek Parsonage, William Boles
1Center for Structural Biology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
Abstract:
The FAD-dependent alpha-glycerophosphate oxidase (GlpO) from Enterococcus casseliflavus and Streptococcus sp. was originally studied as a soluble flavoprotein oxidase; surprisingly, the GlpO sequence is 30-43% identical to those of the alpha-glycerophosphate dehydrogenases (GlpDs) from mitochondrial and bacterial sources. The structure of a deletion mutant of Streptococcus sp. GlpO (GlpODelta, lacking a 50-residue insert that includes a flexible surface region) has been determined using multiwavelength anomalous dispersion data and refined at 2.3 A resolution. Using the GlpODelta structure as a search model, we have also determined the intact GlpO structure, as refined at 2.4 A resolution. The first two domains of the GlpO fold are most closely related to those of the flavoprotein glycine oxidase, where they function in FAD binding and substrate binding, respectively; the GlpO C-terminal domain consists of two helix bundles and is not closely related to any known structure. The flexible surface region in intact GlpO corresponds to a segment of missing electron density that links the substrate-binding domain to a betabetaalpha element of the FAD-binding domain. In accordance with earlier biochemical studies (stabilizations of the covalent FAD-N5-sulfite adduct and p-quinonoid form of 8-mercapto-FAD), Ile430-N, Thr431-N, and Thr431-OG are hydrogen bonded to FAD-O2alpha in GlpODelta, stabilizing the negative charge in these two modified flavins and facilitating transfer of a hydride to FAD-N5 (from Glp) as well. Active-site overlays with the glycine oxidase-N-acetylglycine and d-amino acid oxidase-d-alanine complexes demonstrate that Arg346 of GlpODelta is structurally equivalent to Arg302 and Arg285, respectively; in both cases, these residues interact directly with the amino acid substrate or inhibitor carboxylate. The structural and functional divergence between GlpO and the bacterial and mitochondrial GlpDs is also discussed.
More Related Videos
08:57Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases
Published on: February 24, 2018
11:27X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
Related Concept Videos
Structure of Porins
ATP Synthase: Structure
Pyruvate Oxidation
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
ATP Synthase: Mechanism
Chemiosmosis
Electron Transport Chain
The electron transport chain involves a series of protein complexes on the inner mitochondrial membrane that undergo a series of redox reactions. At the end of this chain, the electrons reduce...
Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...