The Amber Codon in the Gene Encoding the Monomethylamine Methyltransferase Isolated from Methanosarcina barkeri Is Translated as a Sense Codon

James, Carey M.; Ferguson, Tsuneo; Leykam, Joseph F.; Krzycki, Joseph A.

doi:10.1074/jbc.m102929200

Cited by 61 publications

(61 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first hints of the existence of a 22nd genetically encoded amino acid came from studies of monomethylamine methyltransferase in the archaeon Methanosarcina barkeri. It was found that an in-frame UAG stop codon in this gene was translated in vivo as lysine or a lysine derivative (James et al 2001). Subsequent crystallographic data showed that this residue was in fact the novel amino acid pyrrolysine (Hao et al 2002).…”

Section: 21 22 mentioning

confidence: 99%

Aminoacyl-tRNAs: setting the limits of the genetic code

Ibba¹,

Söll²

2004

Genes Dev.

151

117

View full text Add to dashboard Cite

Aminoacyl-tRNAs (aa-tRNAs) are simple molecules with a single purpose-to serve as substrates for translation. They consist of mature tRNAs to which an amino acid has been esterified at the 3Ј-end. The 20 different types of aa-tRNA are made by the 20 different aminoacyl-tRNA synthetases (aaRSs, of which there are two classes), one for each amino acid of the genetic code . This would be fine if it were not for the fact that such a straightforward textbook scenario is not true in a single known living organism. aa-tRNAs lie at the heart of gene expression; they interpret the genetic code by providing the interface between nucleic acid triplets in mRNA and the corresponding amino acids in proteins. The synthesis of aa-tRNAs impacts the accuracy of translation, the expansion of the genetic code, and even provides tangible links to primary metabolism. These central roles vest immense power in aa-tRNAs, and recent studies show just how complex and diverse their synthesis is.

show abstract

Section: 21 22 mentioning

confidence: 99%

Aminoacyl-tRNAs: setting the limits of the genetic code

Ibba¹,

Söll²

2004

Genes Dev.

151

117

View full text Add to dashboard Cite

show abstract

“…This new amino acid is co-translationally inserted in response to an in-frame UAG codon located in the corresponding mRNAs [3]. The insertion of this amino acid relies on the presence of a specific suppressor tRNA (tRNA Pyl ) [4] and the new class II aminoacyl-tRNA synthetase, pyrrolysyl-tRNA synthetase (PylRS) specific only for its substrates tRNA Pyl and Pyl [5,6].…”

Section: Introductionmentioning

confidence: 99%

Pyrrolysine analogues as substrates for pyrrolysyl‐tRNA synthetase

et al. 2006

View full text Add to dashboard Cite

In certain methanogenic archaea a new amino acid, pyrrolysine (Pyl), is inserted at in-frame UAG codons in the mRNAs of some methyltransferases. Pyl is directly acylated onto a suppressor tRNA Pyl by pyrrolysyl-tRNA synthetase (PylRS). Due to the lack of a readily available Pyl source, we looked for structural analogues that could be aminoacylated by PylRS onto tRNA Pyl . We report here the in vitro aminoacylation of tRNA Pyl by PylRS with two Pyl analogues: -prolyl-lysine) and N-e-cyclopentyloxycarbonyl-L L-lysine (Cyc). Escherichia coli, transformed with the tRNA Pyl and PylRS genes, suppressed a lacZ amber mutant dependent on the presence of D D-prolyl-lysine or Cyc in the medium, implying that the E. coli translation machinery is able to use Cyc-tRNA Pyl and D D-prolyl-lysine-tRNA Pyl as substrates during protein synthesis. Furthermore, the formation of active b-galactosidase shows that a specialized mRNA motif is not essential for stop-codon recoding, unlike for selenocysteine incorporation.

show abstract

“…T ranslated in-frame amber (TAG/UAG) codons in the genes encoding methylamine methyltransferases from Methanosarcina barkeri (1)(2)(3) were early clues to the existence of pyrrolysine as the 22nd genetically encoded amino acid from nature. Crystallography of MtmB1, the monomethylamine methyltransferase, demonstrated that the UAG codon of the encoding mtmB1 gene corresponds to pyrrolysine, whose structure was proposed as lysine with N in amide linkage with the D-isomer of 4-methyl-pyrroline-5-carboxylate (4,5).…”

mentioning

confidence: 99%

A natural genetic code expansion cassette enables transmissible biosynthesis and genetic encoding of pyrrolysine

Longstaff

Larue

Faust

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Pyrrolysine has entered natural genetic codes by the translation of UAG, a canonical stop codon. UAG translation as pyrrolysine requires the pylT gene product, an amber-decoding tRNA Pyl that is aminoacylated with pyrrolysine by the pyrrolysyl-tRNA synthetase produced from the pylS gene. The pylTS genes form a gene cluster with pylBCD, whose functions have not been investigated. The pylTSBCD gene order is maintained not only in methanogenic Archaea but also in a distantly related Gram-positive Bacterium, indicating past horizontal gene transfer of all five genes. Here we show that lateral transfer of pylTSBCD introduces biosynthesis and genetic encoding of pyrrolysine into a naïve organism. PylS-based assays demonstrated that pyrrolysine was biosynthesized in Escherichia coli expressing pylBCD from Methanosarcina acetivorans. Production of pyrrolysine did not require tRNA Pyl or PylS. However, when pylTSBCD were coexpressed with mtmB1, encoding the methanogen monomethylamine methyltransferase, UAG was translated as pyrrolysine to produce recombinant monomethylamine methyltransferase. Expression of pylTSBCD also suppressed an amber codon introduced into the E. coli uidA gene. Strains lacking one of the pylBCD genes did not produce pyrrolysine or translate UAG as pyrrolysine. These results indicated that pylBCD gene products biosynthesize pyrrolysine using metabolites common to Bacteria and Archaea and, furthermore, that the pyl gene cluster represents a ''genetic code expansion cassette,'' previously unprecedented in natural organisms, whose transfer allows an existing codon to be translated as a novel endogenously synthesized free amino acid. Analogous cassettes may have served similar functions for other amino acids during the evolutionary expansion of the canonical genetic code.T ranslated in-frame amber (TAG/UAG) codons in the genes encoding methylamine methyltransferases from Methanosarcina barkeri (1-3) were early clues to the existence of pyrrolysine as the 22nd genetically encoded amino acid from nature. Crystallography of MtmB1, the monomethylamine methyltransferase, demonstrated that the UAG codon of the encoding mtmB1 gene corresponds to pyrrolysine, whose structure was proposed as lysine with N in amide linkage with the D-isomer of 4-methyl-pyrroline-5-carboxylate (4, 5). This structure is consistent with the UAG-encoded residue's mass in three distinct methylamine methyltransferases (6).Near the mtmB1 gene in Methanosarcina spp. are the pyl genes (ref. 7; Fig. 1). Two of these genes are known to underlie the genetic encoding of pyrrolysine. The pylT encodes tRNA Pyl , whose CUA anticodon complements the UAG codon corresponding to pyrrolysine. Deletion of the pyl gene promoter and pylT leads to loss of pyrrolysine-dependent monomethylamine methyltransferase and methylamine metabolism (8). The pylS gene encodes the pyrrolysyl-tRNA synthetase, PylS, which charges tRNA Pyl with chemically synthesized pyrrolysine and further carries out a pyrrolysine-dependent ATP:pyrophosphate exchange reaction (5, 9-11)...

show abstract

The Amber Codon in the Gene Encoding the Monomethylamine Methyltransferase Isolated from Methanosarcina barkeri Is Translated as a Sense Codon

Cited by 61 publications

References 35 publications

Aminoacyl-tRNAs: setting the limits of the genetic code

Aminoacyl-tRNAs: setting the limits of the genetic code

Pyrrolysine analogues as substrates for pyrrolysyl‐tRNA synthetase

A natural genetic code expansion cassette enables transmissible biosynthesis and genetic encoding of pyrrolysine

Contact Info

Product

Resources

About