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Proton pumping respiratory complex I is a major player in mitochondrial energy conversion. Yet little is known about the molecular mechanism of this large membrane protein complex. Understanding the details of ubiquinone reduction will be prerequisite for elucidating this mechanism. Based on a
We previously produced the unique ubiquinone QT ("decoupling" quinone), the catalytic reduction of which in NADH-quinone oxidoreduction with bovine heart mitochondrial NADH-ubiquinone oxidoreductase (complex I) is completely decoupled from proton translocation across the membrane domain. This
The Na+-pumping NADH-quinone oxidoreductase (Na+-NQR) is the first enzyme of the respiratory chain and the main ion transporter in many marine and pathogenic bacteria, including Vibrio cholerae The V. cholerae Na+-NQR has been extensively studied, but its binding sites for ubiquinone and inhibitors
Chromatophores from Rhodospirillum rubrum were oriented as multilayers on quartz slides under reducing conditions. Irradiation of these multilayers in the resonance cavity of an ESR spectrometer at 6 K yielded the spectrum of the bacteriochlorophyll dimer triplet. The relative intesities of the main
The X-ray crystal structure of a Rhodobacter sphaeroides reaction center with the mutation Ala M260 to Trp (AM260W) has been determined. Diffraction data were collected that were 97.6% complete between 30.0 and 2.1 A resolution. The electron density maps confirm the conclusions of a previous
Studies on the inhibitory mechanism of acetogenins, the most potent inhibitors of mitochondrial complex I (NADH-ubiquinone oxidoreductase), are useful for elucidating the structural and functional features of the terminal electron transfer step of this enzyme. Previous studies of the
A total of 13 Pasteurellaceae isolates from healthy freshwater turtles were characterized by genotypic and phenotypic tests. Phylogenetic analysis of partial 16S rRNA and rpoB gene sequences showed that the isolates investigated formed a monophyletic group. The closest related species based on 16S
LHON (Leber hereditary optic neuropathy) is a maternally inherited disease that leads to sudden loss of central vision at a young age. There are three common primary LHON mutations, occurring at positions 3460, 11778 and 14484 in the human mtDNA (mitochondrial DNA), leading to amino acid
Effects of prolonged consumption of ubiquinone on myocardial injury caused by ischemia and reperfusion were studied in reperfused rat hearts. Wistar rats received lipophylic or hydrophilic forms of ubiquinone for 6-8 weeks with chow or water, respectively. Isolated isovolumic hearts with a constant
Takeout proteins are found across a diverse range of insect species and are thought to be involved in important aspects of insect physiology and behavior. These proteins act as ligand carriers, but the nature of their endogenous ligands remains unknown. The crystal structure of Epiphyas postvittana
Studies of the structure-activity relationships of ubiquinones and specific inhibitors are helpful to probe the structural and functional features of the ubiquinone reduction site of bovine heart mitochondrial complex I. Bulky exogenous short-chain ubiquinones serve as sufficient electron acceptors
X-ray crystallography has been used to investigate the extent of structural changes in mutants of the purple bacterial reaction center that assemble without a particular ubiquinone or bacteriopheophytin cofactor. In the case of the bacteriopheophytin-exclusion mutant, in which Ala M149 was replaced
A Gram-negative, rod-shaped, non-spore forming and non-motile bacterium, designated strain NUM 1720(T) , was isolated from the oral cavity of bears. Based on 16S rRNA gene sequence similarity, strain NUM 1720(T) was shown to be related to Gibbsiella quercinecans (99.4%). The gyrB and rpoB gene
BACKGROUND
Mitochondrial damage-associated molecular patterns (mtDAMPs), such as mitochondrial DNA and N-formylated peptides, are endogenous molecules released from tissue after traumatic injury. mtDAMPs are potent activators of the innate immune system. They have similarities with bacteria, which
Ubiquinone (UQ) is a polyprenylated lipid that is conserved from bacteria to humans and is crucial to cellular respiration. How the cell orchestrates the efficient synthesis of UQ, which involves the modification of extremely hydrophobic substrates by multiple sequential enzymes, remains an