title: The interaction between biologically inactive tRNA conformers and leucyl-tRNA synthetase from rabbit liver.
abstract: The interaction between tRNA conformers inactive in aminoacylation and leucyl-tRNA synthetase has been investigated. Heat inactivation of the enzyme in the presence of inactive tRNA conformers is shown to lead to a marked increase of inactivation rate while active tRNA conformers, on the other hand, reveal a protecting effect. To study the properties of the enzyme complexed with different tRNA conformers limited proteolysis has been used. Active tRNA conformers are found to protect leucyl-tRNA synthetase against hydrolysis while inactive ones tend to intensify it. Inactive tRNA conformers are also shown to inhibit the aminoacylation of native tRNA in vitro. On the basis of these data biologically inactive conformers of animal tRNA are assumed to form an unproductive complex with leucyl-tRNA synthetase and the structure of the enzyme involved in such interaction is supposed to be more labile and 'extended' than that in complex with active tRNA conformers.
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D006358:Hot Temperature; D007935:Leucine-tRNA Ligase / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism*; D011817:Rabbits; D014357:Trypsin / Q000378:metabolism
chemical_list: D012343:RNA, Transfer; D014357:Trypsin; D000604:Amino Acyl-tRNA Synthetases; D007935:Leucine-tRNA Ligase