| UBC proteins | <protein> Family of proteins involved in conjugating ubiquitin to proteins. UBC1, UBC4 and UBC5 have a role in targeting proteins for degradation, but others have more complex roles, including an involvement in cell cycle control (UBC3) and the secretory pathway (UBC6). (18 Nov 1997) |
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| ubihydroquinone | The reduction product of a ubiquinone. Synonym: ubihydroquinone. (05 Mar 2000) |
| ubiquinol | The reduction product of a ubiquinone. Synonym: ubihydroquinone. (05 Mar 2000) |
| ubiquinol-cytochrome-c reductase | <enzyme> An 11-subunit enzyme complex that acts as an electron transferring protein in the mitochondrial respiratory chain. The enzyme complex catalyses the oxidation of ubiquinol to ubiquinone and ferrocytochrome c in the presence of ferricytochrome c. It contains cytochromes b-562, b-566, and c1 as well as an iron ferredoxin. Chemical name: Ubiquinol-ferricytochrome-c oxidoreductase Registry number: EC 1.10.2.2 (12 Dec 1998) |
| ubiquinone | <biochemistry> Small molecule with a hydrocarbon chain (usually of several isoprene units) that serves as an important electron carrier in the respiratory chain. The acquisition of an electron and a proton by ubiquinone produces ubisemiquinone a free radical), a second proton and electron convert this to dihydroubiquinone. Plastoquinone, which is almost identical to ubiquinone, is the plant form. (18 Nov 1997) |
| ubiquinone-10 | Ubiquinone-50; coenzyme Q10;2,3-Dimethoxy-5-methyl-6-decaprenyl-1,4-benzoquinone. (05 Mar 2000) |
| ubiquinone-6 | Ubiquinone-30; coenzyme Q6;2,3-Dimethoxy-5-methyl-6-hexaprenyl-1,4 benzoquinone. (05 Mar 2000) |
| ubiquitin | <protein> A protein (8.5 kD) found in all eukaryotic cells. Can be linked to the lysine side chains of proteins by formation of an amide bond to its C terminal glycine in an ATP requiring process. The protein/ubiquitin complex is subject to rapid proteolysis. Ubiquitin also has a role in the heat shock response. (18 Nov 1997) |
| ubiquitin carrier protein kinase | <enzyme> A 300 kD kinase consisting of 3 subunits of mws 70, 105 and 120; requires magnesium but inhibited by high concentration; from hela cells Registry number: EC 2.7.10.- (26 Jun 1999) |
| ubiquitin thiolesterase | <enzyme> Cleaves c-terminal enzyme s-ubiquitin and c-terminal adenosine 5'-phosphate ubiquitin; uch-8 is also available Registry number: EC 3.1.2.15 Synonym: ubiquitin c-terminal esterase, ubiquitin carboxy-terminal hydrolase, ubiquitin carboxy-terminal esterase, neuron-specific protein 9.5, pgp 9.5, protein gene product 9.5, uch-l3, ubiquitin c-terminal hydrolase (26 Jun 1999) |
| ubiquitin-calmodulin ligase | <enzyme> Covalentyl links ubiquitin to bovine calmodulin in an ATP-dependent manner Registry number: EC 6.3.2.21 Synonym: ubiquityl-calmodulin synthetase (26 Jun 1999) |
| ubiquitin-Nalpha-protein hydrolase | <enzyme> Cleaves ubiquitin fusion proteins to release ubiquitin and the authentic protein; encoded by gene ubp1 from saccharomyces cerevisiae; amino acid sequence has been determined Registry number: EC 3.4.99.- Synonym: ualphap hydrolase, ubiquitin-conjugate peptidase, alpha-nh-ubiquitin protein endoprotease, ubiquitin-specific processing protease, ubp1 protein, ubp1 gene product, yeast ubiquitin hydrolase, yuh1 protein, yuh1 gene product, ubp2 protease, ubp5 gene product, fat facets gene product (26 Jun 1999) |
| ubiquitin-protein ligase | <enzyme> Consists of 3 enzymes; e1 is ubiquitin activating enzyme; e2 transfers activated ubiquitin as an enzyme-ubiquitin thiol ester to e3, which transfers ubiquitin to an intracellular protein; e1 forms both an enzyme-bound cooh-terminal ubiquitin thiolester and a cooh-terminal ubiquitin-adenylatte; ube1y is putative y function in spermatogonial proliferation; ube1x and ube1y encode the e1 enzyme Registry number: EC 6.3.2.19 Synonym: ubiquitin-protein ligase system, ubiquitin-protein-lysine n-omega-ligase, ubiquitin-activating enzyme, ubiquitin-activating enzyme e1, ubiquitination activating enzyme e1, ube1 gene product, rsp5 ubiquitin-protein ligase, npi1 protein, ube1y gene product, ube1x gene product, ikappab-ubiquitin ligase (26 Jun 1999) |
| ubiquitinoylation | <biochemistry> The covalent addition of ubiquitin residues to proteins. Single or multiple residues can be added and bound ubiquitin can also be a site for further addition of ubiquitin residues. (18 Nov 1997) |
| ubiquity | 1. Existence everywhere, or in places, at the same time; omnipresence; as, the ubiquity of God is not disputed by those who admit his existence. "The arms of Rome . . . Were impeded by . . . The wide spaces to be traversed and the ubiquity of the enemy." (C. Merivale) 2. The doctrine, as formulated by Luther, that Christ's glorified body is omnipresent. Origin: L. Ubique everywhere, fr. Ubi where, perhaps for cubi, quobi (cf. Alicubi anywhere), and if so akin to E. Who: cf. F. Ubiquite. Source: Websters Dictionary (01 Mar 1998) |