ASPARTYL-TRANSFER RNA-SYNTHETASE FROM ESCHERICHIA-COLI - CLONING AND CHARACTERIZATION OF THE GENE, HOMOLOGIES OF ITS TRANSLATED AMINO-ACID-SEQUENCE WITH ASPARAGINYL-TRANSFER RNA AND LYSYL-TRANSFER RNA-SYNTHETASES

作者：ERIANI G^*; DIRHEIMER G; GANGLOFF J

来源：Nucleic Acids Research, 1990, 18(23): 7109-7118.

DOI：10.1093/nar/18.23.7109

By screening of an Escherichia coli plasmidic library using antibodies against aspartyl-tRNA synthetase (AspRS) several clones were obtained containing aspS, the gene coding for AspRS. We report here the nucleotide sequence of aspS and the corresponding primary structure of the aspartyl-tRNA synthetase, a protein of 590 amino acid residues with a Mr 65,913, a value in close agreement with that observed for the purified protein. Primer extension analysis of the aspS mRNA using reverse transcriptase located its 5'-end at 94 nucleotides upstream of the translation initiation AUG; nuclease S1 analysis located the 3'-end at 126 nucleotides downstream of the stop codon UGA. Comparison of the DNA-derived protein sequence with known aminoacyl-tRNA sequences revealed important homologies with asparaginyl- and lysyl-tRNA synthetases from E. coli; more than 25% of their amino acid residues are identical, the homologies being distributed preferencially in the first part and the carboxy-terminal end of the molecule. Mutatgenesis directed towards a consensus tetrapeptide (Gly-Leu-Asp-Arg) and the carboxy-terminal end showed that both domains could be implicated in catalysis as well as in ATP binding.

• 出版日期1990-12-11