Topic
COX5A
About: COX5A is a research topic. Over the lifetime, 44 publications have been published within this topic receiving 4876 citations. The topic is also known as: COX & COX-VA.
Papers
TL;DR: Two possible proton pathways for pumping, each spanning from the matrix to the cytosolic surfaces, were identified, including hydrogen bonds, internal cavities likely to contain water molecules, and structures that could form hydrogen bonds with small possible conformational change of amino acid side chains.
Abstract: The crystal structure of bovine heart cytochrome c oxidase at 2.8 A resolution with an R value of 19.9 percent reveals 13 subunits, each different from the other, five phosphatidyl ethanolamines, three phosphatidyl glycerols and two cholates, two hemes A, and three copper, one magnesium, and one zinc. Of 3606 amino acid residues in the dimer, 3560 have been converged to a reasonable structure by refinement. A hydrogen-bonded system, including a propionate of a heme A (heme a), part of peptide backbone, and an imidazole ligand of CuA, could provide an electron transfer pathway between CuA and heme a. Two possible proton pathways for pumping, each spanning from the matrix to the cytosolic surfaces, were identified, including hydrogen bonds, internal cavities likely to contain water molecules, and structures that could form hydrogen bonds with small possible conformational change of amino acid side chains. Possible channels for chemical protons to produce H2O, for removing the produced water, and for O2, respectively, were identified.
2,178 citations
TL;DR: The effects of manipulating COX4 subunit expression on COX activity, ATP production, O(2) consumption, and reactive oxygen species generation indicate that the COX 4 subunit switch is a homeostatic response that optimizes the efficiency of respiration at different O( 2) concentrations.
1,233 citations
TL;DR: The large number of complementation groups represented by the second and third phenotypic classes suggest that both the expression of the structural genes encoding the nine polypeptide subunits of cytochrome c oxidase and the assembly of these subunits into a functional holoenzyme require the products of many nuclear genes.
176 citations
TL;DR: It is found that aerobic genes are induced faster than hypoxic genes and that transcripts from both types of gene are turned over quickly and have important implications for cytochrome coxidase function and biogenesis and for models of oxygen sensing in yeast.
142 citations
TL;DR: It is found that COX5a is a contiguous gene but thatCOX5b contains an intron, which interrupts the AUG codon that initiates translation of the pre-subunit Vb polypeptide and contains a 5' donor splice sequence that differs from that normally found in yeast introns.
Abstract: In Saccharomyces cerevisiae, subunit V of the inner mitochondrial membrane protein complex cytochrome c oxidase is encoded by two nonidentical genes, COX5a and COX5b. Both genes are present as single copies in S. cerevisiae and in several other Saccharomyces species. Nucleotide sequencing studies with the S. cerevisiae COX5 genes reveal that they encode proteins of 153 and 151 amino acids, respectively. Overall, the coding sequences of COX5a and COX5b have nucleotide and protein homologies of 67 and 66%, respectively. They are saturated for nucleotide substitutions that result in a synonomous codon, indicating a long divergence time between these two genes. Nucleotide sequences flanking the COX5a and COX5b coding regions exhibit no significant homology. The COX5a protein, pre-subunit Va, contains a 20-amino-acid leader peptide, whereas the COX5b protein, pre-subunit Vb, contains a 17-amino-acid leader peptide. These two leader peptides exhibit only 45% homology in the primary sequence, but have similar predicted secondary structures. By analyzing the RNA transcripts from both genes we have found that COX5a is a contiguous gene but that COX5b contains an intron. Surprisingly, the COX5b intron interrupts the AUG codon that initiates translation of the pre-subunit Vb polypeptide and contains a 5' donor splice sequence that differs from that normally found in yeast introns.
109 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2020 | 3 |
| 2019 | 2 |
| 2018 | 1 |
| 2017 | 2 |
| 2016 | 2 |