Summary
Mycoplasma capricolum uses two tryptophan codons, the “universal” nonsense condon UGA and the universal codon UGG. The bacterium contains two tryptophan tRNAs, one with anticodon UCA, (U: 2′-O-methyl U derivative), and the other with CCA (5′-C: partially 2′-O-methylated). tRNAUCA would translate codons UGA and probably UGG by wobbling. tRNACCA is much less charged by tryptophan in the cells than tRNAUCA, and the intracellular amount of tRNACCA is 5–10 times lower than that of tRNAUCA. The genes for these two tRNAs are separated by a terminator-like structure in a single operon. In vitro transcription experiments suggest that the predominance of tRNAUCA over tRNACCA results from the attenuation of transcription by this terminator-like structure.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Barrell BG, Bankier AT, Drouin J (1979) A different genetic code in human mitochondria. Nature 282:189–194
Bünemann H, Westhoff P (1983) Hybrid selection of specific RNAs using DNA covalently coupled to macroporous supports. Methods Enzymol 100:400–407
Crick FHC (1966) Codon-anticodon paring: The wobble hypothesis. J Mol Biol 19:548–555
Hirsh D (1971) Tryptophan transfer RNA as the UGA suppressor. J Mol Biol 58:439–458
Jukes TH (1985) A change in the genetic code in Mycoplasma capriocolum. J Mol Evol 22:361–362
Kuchino Y, Hanyu N, Nishimura S (1987) Analysis of modified nucleosides and nucleotide sequence of tRNA. Methods Enzymol 155:379–396
Maniatis T, Fritsch EF, Sambrook J (1982) Molecular cloning: A laboratory manual. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York
Muto A, Osawa S (1987) The guanine and cytosine content of genomic DNA and bacterial evolution. Proc Natl Acad Sci USA 84:166–169
Nishimura S (1979) Modified nucleosides in tRNA. In: Schimmel PR, Söll D, Abelson JN (eds) Transfer RNA: Structure, properties and recognition. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, pp 59–79
Ohkubo S, Muto A, Kawauchi Y, Yamao F, Osawa S (1987) The ribosomal protein gene cluster of Mycoplasma capriocolum. Mol Gen Genet 210:314–320
Osawa S, Jukes TH, Muto A, Yamao F, Ohama T, Andachi Y (1988) Role of directional mutation pressure in the evolution of the eubacterial genetic code. Cold Spring Harbor Symp Quant Biol 52:in press
Yamao F, Muto A, Kawauchi Y, Iwami M, Iwagami S, Azumi Y, Osawa S (1985) UGA is read as tryptophan in Mycoplasma capriocolum. Proc Natl Acad Sci USA 82:2306–2309
Yokoyama S, Watanabe T, Murao K, Ishikura H, Yamaizumi Z, Nishimura S, Miyazawa T (1985) Molecular mechanism of codon recognition by tRNA species with modified uridine in the first position of the anticodon. Proc Natl Acad Sci USA 82:4905–4909
Author information
Authors and Affiliations
Additional information
Communicated by K. Isono
Rights and permissions
About this article
Cite this article
Yamao, F., Iwagami, S., Azumi, Y. et al. Evolutionary dynamics of tryptophan tRNAs in Mycoplasma capricolum . Mol Gen Genet 212, 364–369 (1988). https://doi.org/10.1007/BF00334708
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00334708