Ligase cytosolic

Coumaroyl-CoA is produced from the amino acid phenylalanine by what has been termed the general phenylpropanoid pathway, through three enzymatic conversions catalyzed by phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), and 4-coumarate CoA ligase (4CL). Malonyl-CoA is formed from acetyl-CoA by acetyl-CoA carboxylase (ACC) (Figure 3.2). Acetyl-CoA may be produced in mitochondria, plastids, peroxisomes, and the cytosol by a variety of routes. It is the cytosolic acetyl-CoA that is used for flavonoid biosynthesis, and it is produced by the multiple subunit enzyme ATP-citrate lyase that converts citrate, ATP, and Co-A to acetyl-CoA, oxaloacetate, ADP, and inorganic phosphate. ... 

Recently a variety of modifiers of ubiquitin ligases have been discovered33 1 as have ubiquitin-like domains in other proteins. These findings elucidate the complexity of the sorting of proteins and removal of improperly folded and otherwise defective proteins from the secretory pathway and return to the proteasomes in the cytosol.dd ee They also suggest important roles for ubiquitination in a broad range of metabolic controls. 

Fatty acids taken into cells are first activated in the cytosol by reaction with CoA and ATP to yield fatty acyl-CoA in a reaction catalyzed by acyl-CoA ligase ... 

A single holocarboxylase synthetase (biotin protein ligase, EC 6.3.4.10) acts on the apoenzymes of acetyl CoA, pyruvate, propionyl CoA, and methylcrotonyl CoA carboxylases. Acetyl CoA carboxylase is a cytosolic enzyme, whereas the other three enzymes are mitochondrial. Although holocarboxylase synthetase is found in both the cytosol and mitochondria, it is not clear whether biotin is incorporated into the mitochondrial enzymes before or after they are translocated into the mitochondria. 

Different mechanisms have been described to explain the toxic effects of PrP in the cytosolic compartment. In one study co-aggregation of misfolded cytoPrP with the anti-apoptotic protein Bcl-2 was shown to coincide with toxicity [71]. Another study reported that cytoPrP can interact with the E3 ubiquitin ligase Mahogunin, thereby disrupting its function [67]. Interestingly, a toxic potential was also observed for cytosolically localized PrPSc, which can inhibit proteasomal activity [69]. 

The major antioxidant molecule, glutathione (GSH), is a tripeptide that is generated within the cytosol via glutamate-cysteine ligase and glutathione synthetase (Valko et al. 2007). This molecule has several... 

The fatty acid in its ionized form is activated in the long-chain-fatty-acid-CoA ligase outer surface of the eukaryotic outer mitochon- q substrates butyrate-CoA... 

Translation involves two compartments the cytosol in which individual amino acids are enzymi-cally attached to their specific tRNAs by amino-acid-tRNA ligases (also called aminoacyl-tRNA synthetases) and the ribosomes in which the amino acids are correctly positioned according to the base sequence of a mRNA template and polymerized into polypeptide chains. 

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