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Proc Natl Acad Sci U S A. 1993 May 15; 90(10): 4723–4727.

Transfer RNAs with complementary anticodons: could they reflect early evolution of discriminative genetic code adaptors?


In accordance with the hypercycle theory of M. Eigen and P. Schuster [(1979) Hypercycle: A Principle of Natural Self-Organization (Springer, New York)], the ancestors of modern tRNAs appear to have emerged via the shortest possible way, both complementary strands of a short symmetrical double helix serving as pre-tRNAs with complementary anticodons. This conclusion is based upon results of comparative sequence analysis of the 17-base-long anticodon loop and stem of tRNAs totaling 896 and especially of 22 pairs of consensus tRNAs with complementary or quasi-complementary anticodons. With regard to the anticodon loop and stem of pairs of consensus tRNAs, complementary distances were considerably less than direct distances--i.e., antiparallel pairing invariably yielded fewer mismatches than direct pairing. Furthermore, the smallest complementary distance was detected when two antiparallel sequences formed irregular G-U bonds in their anticodon triplets. The above implies that pre-tRNAs in peribiotic times were long hairpin structures having 73 bases or more, the middle base of an anticodon being the center of symmetry. Accordingly, each pair of pre-tRNAs with complementary anticodons should have been almost identical with each other except for their three central bases. The above situation appears to have dictated the early establishment of direct links between anticodons and the type of amino acids with which tRNAs are to be charged. This direct link is still maintained between modern aminoacyl-tRNA synthetases and anticodons. Replication of the double helices concertedly generated new codons for the same pair of amino acids. Thus, occurrence of synonymous as well as certain "palindromic" features of the genetic code table might have been determined by this mechanism.

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  • Ohno S. Universal rule for coding sequence construction: TA/CG deficiency-TG/CT excess. Proc Natl Acad Sci U S A. 1988 Dec;85(24):9630–9634. [PMC free article] [PubMed]
  • Yomo T, Ohno S. Concordant evolution of coding and noncoding regions of DNA made possible by the universal rule of TA/CG deficiency-TG/CT excess. Proc Natl Acad Sci U S A. 1989 Nov;86(21):8452–8456. [PMC free article] [PubMed]
  • Ohno S, Yomo T. Various regulatory sequences are deprived of their uniqueness by the universal rule of TA/CG deficiency and TG/CT excess. Proc Natl Acad Sci U S A. 1990 Feb;87(3):1218–1222. [PMC free article] [PubMed]
  • Ohno S, Yomo T. The grammatical rule for all DNA: junk and coding sequences. Electrophoresis. 1991 Feb-Mar;12(2-3):103–108. [PubMed]
  • Eigen M, Lindemann BF, Tietze M, Winkler-Oswatitsch R, Dress A, von Haeseler A. How old is the genetic code? Statistical geometry of tRNA provides an answer. Science. 1989 May 12;244(4905):673–679. [PubMed]
  • Zharkikh AA, Rzhetsky AYu, Morosov PS, Sitnikova TL, Krushkal JS. VOSTORG: a package of microcomputer programs for sequence analysis and construction of phylogenetic trees. Gene. 1991 May 30;101(2):251–254. [PubMed]
  • Eigen M, Winkler-Oswatitsch R, Dress A. Statistical geometry in sequence space: a method of quantitative comparative sequence analysis. Proc Natl Acad Sci U S A. 1988 Aug;85(16):5913–5917. [PMC free article] [PubMed]
  • Schulman LH, Pelka H. Anticodon switching changes the identity of methionine and valine transfer RNAs. Science. 1988 Nov 4;242(4879):765–768. [PubMed]
  • Rould MA, Perona JJ, Steitz TA. Structural basis of anticodon loop recognition by glutaminyl-tRNA synthetase. Nature. 1991 Jul 18;352(6332):213–218. [PubMed]
  • Crick FH, Brenner S, Klug A, Pieczenik G. A speculation on the origin of protein synthesis. Orig Life. 1976 Dec;7(4):389–397. [PubMed]
  • Bibb MJ, Van Etten RA, Wright CT, Walberg MW, Clayton DA. Sequence and gene organization of mouse mitochondrial DNA. Cell. 1981 Oct;26(2 Pt 2):167–180. [PubMed]
  • Wissinger B, Brennicke A, Schuster W. Regenerating good sense: RNA editing and trans splicing in plant mitochondria. Trends Genet. 1992 Sep;8(9):322–328. [PubMed]
  • Bridson PK, Orgel LE. Catalysis of accurate poly(C)-directed synthesis of 3'-5'-linked oligoguanylates by Zn2+. J Mol Biol. 1980 Dec 25;144(4):567–577. [PubMed]

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