J. Heck - Academia.edu (original) (raw)
Related Authors
North-Eastern Hill University, Hill Univ. Shillong-793022 (India)
Uploads
Papers by J. Heck
Journal of Biological Chemistry
The DNA nucleotide sequence of the v d S gene encoding valyl-tRNA synthetase of Escherichia coli ... more The DNA nucleotide sequence of the v d S gene encoding valyl-tRNA synthetase of Escherichia coli has been determined. The deduced primary structure of valyl-tRNA synthetase was compared to the primary sequences of the known aminoacyl-tRNA synthetases of yeast and bacteria. Significant homology was detected between valyl-tRNA synthetase of E. coli and other known branched-chain aminoacyl-tRNA synthetases. In pairwise comparisons the highest level of homology was detected between the homologous valyl-tRNA synthetases of yeast and E. coli, with an observed 41% direct identity overall. Comparisons between the valyl-and isoleucyl-tRNA synthetases of E. coli yielded the highest level of homology detected between heterologous enzymes (19.2% direct identity overall). An alignment is presented between the three branchedchain aminoacyl-tRNA synthetases (valyl-and isoleucyl-tRNA synthetases of E. coli and yeast mitochondrial leucyl-tRNA synthetase) illustrating the close relatedness of these enzymes. These results give credence to the supposition that the branched-chain aminoacyl-tRNA synthetases along with methionyl-tRNA synthetase form a family of genes within the aminoacyl-tRNA synthetases that evolved from a common ancestral progenitor gene.
Journal of Biological Chemistry
The DNA nucleotide sequence of the v d S gene encoding valyl-tRNA synthetase of Escherichia coli ... more The DNA nucleotide sequence of the v d S gene encoding valyl-tRNA synthetase of Escherichia coli has been determined. The deduced primary structure of valyl-tRNA synthetase was compared to the primary sequences of the known aminoacyl-tRNA synthetases of yeast and bacteria. Significant homology was detected between valyl-tRNA synthetase of E. coli and other known branched-chain aminoacyl-tRNA synthetases. In pairwise comparisons the highest level of homology was detected between the homologous valyl-tRNA synthetases of yeast and E. coli, with an observed 41% direct identity overall. Comparisons between the valyl-and isoleucyl-tRNA synthetases of E. coli yielded the highest level of homology detected between heterologous enzymes (19.2% direct identity overall). An alignment is presented between the three branchedchain aminoacyl-tRNA synthetases (valyl-and isoleucyl-tRNA synthetases of E. coli and yeast mitochondrial leucyl-tRNA synthetase) illustrating the close relatedness of these enzymes. These results give credence to the supposition that the branched-chain aminoacyl-tRNA synthetases along with methionyl-tRNA synthetase form a family of genes within the aminoacyl-tRNA synthetases that evolved from a common ancestral progenitor gene.