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Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET
Published on: October 9, 2021
A tRNA(Glu) that uncouples protein and tetrapyrrole biosynthesis
Gloria Levicán1, Assaf Katz, Patricio Valenzuela
1Programa de Biologia Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Casilla 70086, Santiago 838-0453, Chile.
Abstract:
Glu-tRNA is either bound to elongation factor Tu to enter protein synthesis or is reduced by glutamyl-tRNA reductase (GluTR) in the first step of tetrapyrrole biosynthesis in most bacteria, archaea and in chloroplasts. Acidithiobacillus ferrooxidans, a bacterium that synthesizes a vast amount of heme, contains three genes encoding tRNA(Glu). All tRNA(Glu) species are substrates in vitro of GluRS1 from A. ferrooxidans.Glu-tRNA(3)(Glu), that fulfills the requirements for protein synthesis, is not substrate of GluTR. Therefore, aminoacylation of tRNA(3)(Glu) might contribute to ensure protein synthesis upon high heme demand by an uncoupling of protein and heme biosynthesis.
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