2j5b | pdb_00002j5b
Structure of the Tyrosyl tRNA synthetase from Acanthamoeba polyphaga Mimivirus complexed with tyrosynol
Structural highlights
Function[SYY_MIMIV] Catalyzes the attachment of tyrosine to tRNA(Tyr) in a two-step reaction: tyrosine is first activated by ATP to form Tyr-AMP and then transferred to the acceptor end of tRNA(Tyr) (By similarity).[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAminoacyl-tRNA synthetases are pivotal in determining how the genetic code is translated in amino acids and in providing the substrate for protein synthesis. As such, they fulfill a key role in a process universally conserved in all cellular organisms from their most complex to their most reduced parasitic forms. In contrast, even complex viruses were not found to encode much translation machinery, with the exception of isolated components such as tRNAs. In this context, the discovery of four aminoacyl-tRNA synthetases encoded in the genome of mimivirus together with a full set of translation initiation, elongation, and termination factors appeared to blur what was once a clear frontier between the cellular and viral world. Functional studies of two mimivirus tRNA synthetases confirmed the MetRS specificity for methionine and the TyrRS specificity for tyrosine and conformity with the identity rules for tRNA(Tyr) for archea/eukarya. The atomic structure of the mimivirus tyrosyl-tRNA synthetase in complex with tyrosinol exhibits the typical fold and active-site organization of archaeal-type TyrRS. However, the viral enzyme presents a unique dimeric conformation and significant differences in its anticodon binding site. The present work suggests that mimivirus aminoacyl-tRNA synthetases function as regular translation enzymes in infected amoebas. Their phylogenetic classification does not suggest that they have been acquired recently by horizontal gene transfer from a cellular host but rather militates in favor of an intricate evolutionary relationship between large DNA viruses and ancestral eukaryotes. Virus-encoded aminoacyl-tRNA synthetases: structural and functional characterization of mimivirus TyrRS and MetRS.,Abergel C, Rudinger-Thirion J, Giege R, Claverie JM J Virol. 2007 Nov;81(22):12406-17. Epub 2007 Sep 12. PMID:17855524[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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