1. A single tRNA base pair mediates bacterial tRNA-dependent biosynthesis of asparagine
- Author
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Stamatina Giannouli, Marc Bailly, Mickaël Blaise, Hubert Dominique Becker, Daniel Kern, Constantinos Stathopoulos, Architecture et réactivité de l'ARN (ARN), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche en Infectiologie de Montpellier (IRIM), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Base pair ,[SDV]Life Sciences [q-bio] ,Nitrogenous Group Transferases ,Sequence alignment ,RNA, Archaeal ,[SDV.BC]Life Sciences [q-bio]/Cellular Biology ,Neisseria meningitidis ,Biology ,Substrate Specificity ,03 medical and health sciences ,chemistry.chemical_compound ,RNA, Transfer ,Species Specificity ,Biosynthesis ,RNA, Transfer, Gln ,Genetics ,Nucleotide ,Asparagine ,Uridine ,030304 developmental biology ,Glutamine amidotransferase ,chemistry.chemical_classification ,RNA, Transfer, Asp ,0303 health sciences ,Base Sequence ,RNA, Transfer, Asn ,Adenine ,030302 biochemistry & molecular biology ,RNA, Transfer, Glu ,Amino acid ,Kinetics ,RNA, Bacterial ,Biochemistry ,chemistry ,Transfer RNA ,RNA ,Sequence Alignment - Abstract
In many prokaryotes and in organelles asparagine and glutamine are formed by a tRNA-dependent amidotransferase (AdT) that catalyzes amidation of aspartate and glutamate, respectively, mischarged on tRNAAsn and tRNAGln. These pathways supply the deficiency of the organism in asparaginyl- and glutaminyl-tRNA synthtetases and provide the translational machinery with Asn-tRNAAsn and Gln-tRNAGln. So far, nothing is known about the structural elements that confer to tRNA the role of a specific cofactor in the formation of the cognate amino acid. We show herein, using aspartylated tRNAAsn and tRNAAsp variants, that amidation of Asp acylating tRNAAsn is promoted by the base pair U1-A72 whereas the G1-C72 pair and presence of the supernumerary nucleotide U20A in the D-loop of tRNAAsp prevent amidation. We predict, based on comparison of tRNAGln and tRNAGlu sequence alignments from bacteria using the AdT-dependent pathway to form Gln-tRNAGln, that the same combination of nucleotides also rules specific tRNA-dependent formation of Gln. In contrast, we show that the tRNA-dependent conversion of Asp into Asn by archaeal AdT is mainly mediated by nucleotides G46 and U47 of the variable region. In the light of these results we propose that bacterial and archaeal AdTs use kingdom-specific signals to catalyze the tRNA-dependent formations of Asn and Gln.
- Published
- 2006
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