Purification and partial amino acid sequence of a glutamyl-tRNA synthetase from Rhizobium meliloti

1989 ◽  
Vol 67 (10) ◽  
pp. 674-679 ◽  
Author(s):  
Serge Laberge ◽  
Manon Belair ◽  
Alain Verreault ◽  
Alexander W. Bell ◽  
Lucien M. Bordeleau ◽  
...  

A glutamyl-tRNA synthetase has been purified to homogeneity from Rhizobium meliloti, using reversed-phase chromatography as the last step. Amino acid sequencing of the amino-terminal region of the enzyme indicates that it contains a single polypeptide, whose molecular weight is about 54 000, as judged by SDS–gel electrophoresis. The primary structures of the amino-terminus region and of an internal peptide obtained by cleavage of the enzyme with CNBr have similarities of 58 and 48% with regions of the glutamyl-tRNA sythetase of Escherichia coli; these are thought to be involved in the binding of ATP and tRNA, respectively. The small amount of glutamyl-tRNA synthetase present in R. meliloti is consistent with the metabolic regulation of the biosynthesis of many aminoacyl-tRNA synthetases.Key words: glutamyl-tRNA synthetase, Rhizobium meliloti, purification, reverse-phase chromatography, amino acid sequence.

1999 ◽  
Vol 181 (11) ◽  
pp. 3582-3586 ◽  
Author(s):  
Clifton V. Franklund ◽  
Joanna B. Goldberg

ABSTRACT The glutamyl-tRNA synthetase (gltX) gene fromPseudomonas aeruginosa was identified. A plasmid containing a 2.3-kb insert complemented the temperature-sensitive gltXmutation of Escherichia coli JP1449, and GltX activity was demonstrated. The inferred amino acid sequence of this gene showed 50.6% identity with GltX from Rhizobium meliloti.


1985 ◽  
Vol 227 (3) ◽  
pp. 1003-1007 ◽  
Author(s):  
C M Beach ◽  
S K Chan ◽  
T C Vanaman ◽  
M S Coleman

Terminal deoxynucleotidyltransferase exists in multiple Mr forms, all apparently generated from a single polypeptide of 62kDa. On isolation and purification, the smallest catalytically active protein of this enzyme consists of two subunits, alpha (12kDa) and beta (30kDa). Recently a complementary-DNA nucleotide sequence has been reported for a portion of the enzyme from human lymphoblast. We have pinpointed the locations of the alpha- and beta-subunits within the elucidated nucleotide sequence. From these data, the portions of the nucleotide sequence coding for the catalytically important area of the transferase can be estimated. Here the amino acid sequence of a number of tryptic peptides from calf alpha- and beta-subunits is presented. Because of the striking homology between the amino acid sequence of the calf enzyme and that predicted for human lymphoblast enzyme, it is possible for us to conclude that the alpha-subunit was generated from the C-terminus of the precursor protein and the beta-subunit was non-overlapping and proximal.


1999 ◽  
Vol 338 (3) ◽  
pp. 583-589 ◽  
Author(s):  
Tsuyoshi SHISHIBORI ◽  
Yuhta OYAMA ◽  
Osamu MATSUSHITA ◽  
Kayoko YAMASHITA ◽  
Hiromi FURUICHI ◽  
...  

To investigate the roles of calcium-binding proteins in degranulation, we used three anti-allergic drugs, amlexanox, cromolyn and tranilast, which inhibit IgE-mediated degranulation of mast cells, as molecular probes in affinity chromatography. All of these drugs, which have different structures but similar function, scarcely bound to calmodulin in bovine lung extract, but bound to the same kinds of calcium-binding proteins, such as the 10-kDa proteins isolated in this study, calcyphosine and annexins I–V. The 10-kDa proteins obtained on three drug-coupled resins and on phenyl-Sepharose were analysed by reversed-phase HPLC. It was found that two characteristic 10-kDa proteins, one polar and one less polar, were bound with all three drugs, although S100A2 (S100L), of the S100 family, was bound with phenyl-Sepharose. The cDNA and deduced amino acid sequence proved our major polar protein to be identical with the calcium-binding protein in bovine amniotic fluid (CAAF1, S100A12). The cDNA and deduced amino acid sequence of the less-polar protein shared 95% homology with human and mouse S100A13. In addition, it was demonstrated that the native S100A12 and recombinant S100A12 and S100A13 bind to immobilized amlexanox. On the basis of these findings, we speculate that the three anti-allergic drugs might inhibit degranulation by binding with S100A12 and S100A13.


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