Evolution of genes, evolution of species: the case of aminoacyl-tRNA synthetases.
Mol Biol Evol
; 15(11): 1548-61, 1998 Nov.
Article
en En
| MEDLINE
| ID: mdl-12572618
ABSTRACT
All of the aminoacyl-tRNA synthetase (aaRS) sequences currently available in the data banks have been subjected to a systematic analysis aimed at finding gene duplications, genetic recombinations, and horizontal transfers. Evidence is provided for the occurrence (or probable occurrence) of such phenomena within this class of enzymes. In particular, it is suggested that the monomeric PheRS from the yeast mitochondrion is a chimera of the alpha and beta chains of the standard tetrameric protein. In addition, it is proposed that the dimeric and tetrameric forms of GlyRS are the result of a double and independent acquisition of the same specificity within two different subclasses of aaRS. The phylogenetic reconstructions of the evolutionary histories of the genes encoding aaRS are shown to be extremely diverse. While large segments of the population are consistent with the broad grouping into the three Woesian domains, some phylogenetic reconstructions do not place the Archae and the Eucarya as sister groups but, rather, show a gram-negative bacteria/eukaryote clustering. In addition, many individual genes pose difficulties that preclude any simple evolutionary scheme. Thus, aaRS's are clearly a paradigm of F. Jacob's "odd jobs of evolution" but, on the whole, do not call into question the evolutionary scenario originally proposed by Woese and subsequently refined by others.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Evolución Molecular
/
Genes
/
Aminoacil-ARNt Sintetasas
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Biol Evol
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
1998
Tipo del documento:
Article
País de afiliación:
Francia