title: The role of zinc in 5',5'-diadenosine tetraphosphate production by aminoacyl-transfer RNA synthetases.
abstract: Aminoacyl-tRNA synthetases are capable of converting 5'-ATP into 5',5'-diadenosine tetraphosphate. The reaction reflects the reversal of enzyme-bound aminoacyl-adenylate by ATP instead of PPi. In the case of a few prokaryotic as well as eukaryotic aminoacyl-tRNA synthetases, the initial rate of diadenosine tetraphosphate synthesis can be greatly enhanced upon adding small amounts of zinc. This observation enables us to establish a relationship between diadenosine tetraphosphate, a nucleotide possibly involved in controlling cell proliferation, and a metallic cofactor, which is believed to play a role in tumour growth.
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism*; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D002104:Cadmium / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D015226:Dinucleoside Phosphates; D004926:Escherichia coli / Q000201:enzymology; D015032:Zinc / Q000494:pharmacology*
chemical_list: D000227:Adenine Nucleotides; D015226:Dinucleoside Phosphates; D002104:Cadmium; C020733:diadenosine tetraphosphate; D000604:Amino Acyl-tRNA Synthetases; D015032:Zinc