Publication Date:
2009-01-02
Description:
Pyrrolysine (Pyl), the 22nd natural amino acid, is genetically encoded by UAG and inserted into proteins by the unique suppressor tRNA(Pyl) (ref. 1). The Methanosarcinaceae produce Pyl and express Pyl-containing methyltransferases that allow growth on methylamines. Homologous methyltransferases and the Pyl biosynthetic and coding machinery are also found in two bacterial species. Pyl coding is maintained by pyrrolysyl-tRNA synthetase (PylRS), which catalyses the formation of Pyl-tRNA(Pyl) (refs 4, 5). Pyl is not a recent addition to the genetic code. PylRS was already present in the last universal common ancestor; it then persisted in organisms that utilize methylamines as energy sources. Recent protein engineering efforts added non-canonical amino acids to the genetic code. This technology relies on the directed evolution of an 'orthogonal' tRNA synthetase-tRNA pair in which an engineered aminoacyl-tRNA synthetase (aaRS) specifically and exclusively acylates the orthogonal tRNA with a non-canonical amino acid. For Pyl the natural evolutionary process developed such a system some 3 billion years ago. When transformed into Escherichia coli, Methanosarcina barkeri PylRS and tRNA(Pyl) function as an orthogonal pair in vivo. Here we show that Desulfitobacterium hafniense PylRS-tRNA(Pyl) is an orthogonal pair in vitro and in vivo, and present the crystal structure of this orthogonal pair. The ancient emergence of PylRS-tRNA(Pyl) allowed the evolution of unique structural features in both the protein and the tRNA. These structural elements manifest an intricate, specialized aaRS-tRNA interaction surface that is highly distinct from those observed in any other known aaRS-tRNA complex; it is this general property that underlies the molecular basis of orthogonality.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2648862/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2648862/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nozawa, Kayo -- O'Donoghue, Patrick -- Gundllapalli, Sarath -- Araiso, Yuhei -- Ishitani, Ryuichiro -- Umehara, Takuya -- Soll, Dieter -- Nureki, Osamu -- R01 GM022854/GM/NIGMS NIH HHS/ -- R01 GM022854-33/GM/NIGMS NIH HHS/ -- England -- Nature. 2009 Feb 26;457(7233):1163-7. doi: 10.1038/nature07611. Epub 2008 Dec 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, B34 4259 Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19118381" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acyl-tRNA Synthetases/*chemistry/genetics/*metabolism
;
Aminoacylation
;
Crystallography, X-Ray
;
Desulfitobacterium/*enzymology/genetics
;
Escherichia coli/genetics
;
Lysine/*analogs & derivatives/biosynthesis/genetics/metabolism
;
Methanosarcina barkeri/enzymology/genetics
;
Models, Molecular
;
RNA, Transfer, Amino Acid-Specific/genetics/metabolism
;
Structural Homology, Protein
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
