Gene Ontology annotation through association of InterPro records with GO terms
Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity
Annotation inferences using phylogenetic trees
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PAINT/IBA phylogenetic propagation supports Complex II membership, TCA cycle involvement, mitochondrial inner-membrane localization, and the succinate-to-ubiquinone electron transport process for SDHD across SDHD/CybS orthologs.
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
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UniProt keyword mapping (Electron transport, Mitochondrion, Membrane, Tricarboxylic acid cycle) propagates Complex II / OXPHOS process and localization annotations to SDHD.
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Automatic transfer of experimentally verified manual GO annotation data to orthologs using Ensembl Compara
Combined Automated Annotation using Multiple IEA Methods
Falcon deep research synthesis for human SDHD
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SDHD encodes the small cytochrome b-like membrane subunit of mitochondrial Complex II, partnering with SDHC to anchor the catalytic SDHA/SDHB dimer, harbor heme b, and form the ubiquinone-binding entrance channel.
"The SDHD gene (chromosome 11q23.1) encodes the small cytochrome b-like membrane subunit of mitochondrial Complex II (succinate dehydrogenase; SQR), partnering with SDHC to anchor the catalytic SDHA/SDHB dimer, harbor heme b, and form the ubiquinone-binding/channel region"
Human complex II (succinate-ubiquinone oxidoreductase): cDNA cloning of iron sulfur (Ip) subunit of liver mitochondria.
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Complex II is an important enzyme complex of both the TCA cycle and aerobic respiratory chains. The iron-sulfur subunit of human liver mitochondrial Complex II was cloned from cDNA.
"Complex II (succinate-ubiquinone oxidoreductase) is an important enzyme complex of both the tricarboxylic acid cycle and of the aerobic respiratory chains of mitochondria in eukaryotic cell and prokaryotic organisms"
Assembly of mammalian oxidative phosphorylation complexes I-V and supercomplexes.
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Review of OXPHOS complex assembly including Complex II. Complex II assembly involves SDHAF assembly factors and proceeds via SDHA flavinylation and SDHB Fe-S maturation before SDHC/SDHD membrane integration.
"The assembly of the five oxidative phosphorylation system (OXPHOS) complexes in the inner mitochondrial membrane is an intricate process"
A reference map of the human binary protein interactome.
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High-throughput Y2H screen detecting SDHD interaction with RHBDD2 (Q6NTF9-3). This is a systematic proteome-wide binary interactome study.
"Here we present a human 'all-by-all' reference interactome map of human binary protein interactions, or 'HuRI'"
Quantitative high-confidence human mitochondrial proteome and its dynamics in cellular context.
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SDHD detected in the high-confidence human mitochondrial proteome by quantitative mass spectrometry.
"We classified >8,000 proteins in mitochondrial preparations of human cells and defined a mitochondrial high-confidence proteome of >1,100 proteins (MitoCoP)"
Structure of the human respiratory complex II.
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Cryo-EM structure of human Complex II at 2.86 angstrom resolution showing all four subunits (SDHA, SDHB, SDHC, SDHD). SDHD has three transmembrane helices. Ubiquinone binds at the entrance pocket formed by SDHC TM1, SDHD TM2, and SDHB C-terminus. SDHD Tyr114 directly contacts ubiquinone. His102 of SDHD coordinates heme b as axial ligand. Heme b serves as electron sink with 6.6 angstrom edge-to-edge distance to both ubiquinone and [3Fe-4S]. Disease-relevant SDHD mutations (E69K, D92G) are mapped onto the structure.
"UQ is also observed to bind at the entrance of the pocket formed by the transmembrane helix I of SDHC, transmembrane helix II of SDHD, and the C-terminal segment of SDHB. It interacts with Pro-SDHB197, Trp-SDHB201, Ile-SDHB246, Ile-SDHC56, Trp-SDHC61, Met-SDHC65, Ile-SDHC69, and Tyr-SDHD114"
Cytochrome b in human complex II (succinate-ubiquinone oxidoreductase): cDNA cloning of the components in liver mitochondria and chromosome assignment of the genes for the large (SDHC) and small (SDHD) subunits to 1q21 and 11q23.
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Original cloning of SDHD (cybS) cDNA from human liver. SDHD encodes a 103 amino acid mature protein with three transmembrane segments serving as membrane anchor for Complex II. Histidine residues in the second transmembrane segment are potential heme axial ligands. SDHD gene mapped to chromosome 11q23.
"The mature cybL and cybS contain 140 and 103 amino acids, respectively, and show little similarity to the amino acid sequences of the subunits from other species in contrast to the highly conserved features of the flavoprotein (Fp) subunit and iron-sulfur protein (Ip) subunit"
SDH complex dehydrogenates succinate
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Reactome reaction for SDH-catalyzed succinate oxidation to fumarate with electron transfer to ubiquinone in the inner mitochondrial membrane.
"The succinate dehydrogenase complex (SDH, complex II), associated with the inner mitochondrial membrane, catalyzes the dehydrogenation of succinate to fumarate, reducing ubiquinone (Q10) to ubiquinol (Q10H2) on the membrane part of the enzyme"
SDHA:SDHB binds to SDHC:SDHD
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Reactome reaction describing assembly of the SDHA/SDHB catalytic dimer with the SDHC/SDHD membrane anchor dimer in the inner mitochondrial membrane.
"After translation in cytosol and translocation to the mitochondrial inner membrane SDH subunits C and D (SDHC, SDHD), together with the heme b cofactor, bind to the assembled cytosolic SDHA:SDHB construct to form the fully functional SDH complex"