The Last Common Ancestor: What's in a name?
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Twenty completely sequenced cellular genomes from the three major domains were analyzed using twice one-way BLAST searches in order to define the set of the most conserved protein-encoding sequences to characterize the gene complement of the last common ancestor of extant life. The resulting set is dominated by different putative ATPases, and by molecules involved in gene expression and RNA metabolism. DEAD-type RNA helicase and enolase genes, which are known to be part of the RNA degradosome, are as conserved as many transcription and translation genes. This suggests the early evolution of a control mechanism for gene expression at the RNA level, providing additional support to the hypothesis that during early cellular evolution RNA molecules played a more prominent role. Conserved sequences related to biosynthetic pathways include those encoding putative phosphoribosyl pyrophosphate synthase and thioredoxin, which participate in nucleotide metabolism. Although the information contained in the available databases corresponds only to a minor portion of biological diversity, the sequences reported here are likely to be part of an essential and highly conserved pool of proteins domains common to all organisms.
Keywordslast common ancestor cenancestor RNA/protein world progenote
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- Becerra-Bracho, A., Velasco, A.M., Islas, S., Silva, E., Lloret, S. and Lazcano, A.: 2000, Molecular Biology and the Reconstruction of Microbial Phylogenies: Des Laisions Dangereuses? In J. Chela-Flores, G. Lemerchand, and J. Oró (eds), Origins from the Big-Bang to Biology: Proceedings of the First Ibero-American School of Astrobiology, Klüwer Academic Publishers, Dordrecht, pp. 135–150.Google Scholar
- Böhlke, K., Pisani, F.M., Vorgias, C.E., Frey, B., Sobek, H., Rossi, M. and Antranikian, G.: 2000, PCR Performance of the B-type DNA Polymerase from the Thermophilic Euryarchaeon Thermococcus aggregans Improved by Mutations in the Y-GG/A Motif, Nucleic Acid Res. 28: 3910–3917.Google Scholar
- Delaye, L. and Lazcano, A.: 2000, RNA-Binding Peptides as Molecular Fossils in J. Chela-Flores, G. Lemerchand, and J. Oró (eds), Origins from the Big-Bang to Biology: Proceedings of the First Ibero-American School of Astrobiology, Kluwer Academic Publishers, Dordrecht, pp. 285–288.Google Scholar
- Delaye, L., Becerra, A. and Lazcano, A.: 2002, The Nature of the Last Common Ancestor in Lluis Ribas de Pouplana (ed), The Genetic Code and the Origin of Life, Landes Bioscience, Georgetown, in press.Google Scholar
- Fox, G.E., Luehrsen, K.R. and Woese, C.R.: 1982, Archaebacterial 5S Ribosomal RNA, Zbl. Bakt. Hyg. I Abt. Orig. C3, 330–345.Google Scholar
- Haldane, J.B.S.: 1965, Data Needed for the Blueprint of the First Organism. In Fox, S. W. (ed), The Origin of Prebiological Systems and their Molecular Matrices, Academic Press, New York, pp. 11–15.Google Scholar
- Kandler, O.: 1994, The early diversification of life. In Stefan Bengtson: (ed), Early Life on Earth: Nobel Symposium No. 84, Columbia University Press/Nobel Foundation, New York, pp. 152–160.Google Scholar
- Klenk, H.-P., Palm, P., Zillig, W.: 1993, DNA-Dependent RNA Polymerases as Phylogenetic Markers Molecules, Syst. Appl. Microbiol. 16, 138–147.Google Scholar
- Lazcano, A.: 1995, Cellular Evolution During the Early Archean: What Happened Between the Progenote and the Cenancestor? Microbiologia SEM 11, 185–198.Google Scholar
- Lazcano, A., Fox, G.E. and Oró, J.: 1992, Life before DNA: The Origin and Early Evolution of Early Archean Cells. In R.P. Mortlock: (ed), The Evolution of Metabolic Function, CRC Press, Boca Raton, FL, pp. 237–295.Google Scholar
- Oparin, A.I.: 1961, Life: Its nature, origin and development: Oliver and Boyd, Edinburgh,Google Scholar
- Reanney, D.C.: 1979, RNA Splicing and Polynucleotide Evolution, Nature 227, 597–600.Google Scholar
- Rich, A.: 1962, On the Problems of Evolution and Biochemical Information Transfer. In Kasha, M. and Pullman, B.: (eds), Horizons in Biochemistry, Academic Press, New York, pp. 103–126.Google Scholar
- Woese, C.R.: 1983, The Primary Lines of Descent and the Universal Ancestor. In D. S. Bendall (ed), Evolution from Molecules to Men, Cambridge University Press, Cambridge, pp. 209–233.Google Scholar
- Woese, C.R.: 1987, Bacterial Evolution. Microbiol, Reviews 51, 221–271.Google Scholar