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Aminoacyl-tRNA Synthetases from Bacillus stearothermophilus. Asymmetry of Substrate Binding to Tyrosyl-tRNA Synthetase
| Content Provider | Scilit |
|---|---|
| Author | Bosshard, Hans Rudolf Koch, Gordon L. E. Hartley, Brian S. |
| Copyright Year | 1975 |
| Description | Journal: Journal of Biological Inorganic Chemistry The interaction of L-tyrosine, L-tyrosyladenylate and tRNA-Tyr with tyrosyl-tRNA synthetase from Bacillus stearothermophilus was studied by equilibrium dialysis, gel filtration and fluorescence spectroscopy. The enzyme, which consists of two identical subunits (mol. wt 2 x 44000), binds only a single molecule of L-tyrosine per dimer with a K-d of 2 x 10-5 M at pH 7.8 and 23 degrees C. The tyrosyl-tRNA synthetase--tyrosyladenylate complex which was isolated by gel filtration also has one adenylate bound per dimeric enzyme molecule. In contrast, two tRNA-Tyr molecules bind per enzyme dimer, but the two binding sites are not equivalent having K-d values of 2 x 10-7 M and 1.3 x 10-6 M respectively at pH 6.5 and 25 degrees C. Since crystallographic analysis of the free enzyme [2] shows that the monomer is the asymmetric unit, the data indicate that substrate binding induces asymmetry in the enzyme. |
| Related Links | http://onlinelibrary.wiley.com/doi/10.1111/j.1432-1033.1975.tb04091.x/pdf |
| Ending Page | 498 |
| Page Count | 6 |
| Starting Page | 493 |
| ISSN | 09498257 |
| e-ISSN | 14321327 |
| DOI | 10.1111/j.1432-1033.1975.tb04091.x |
| Journal | Journal of Biological Inorganic Chemistry |
| Issue Number | 2 |
| Volume Number | 53 |
| Language | English |
| Publisher | Wiley-Blackwell |
| Publisher Date | 1975-05-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: Journal of Biological Inorganic Chemistry Biochemistry and Molecular Biology Stearothermophilus Tyrosyl Trna Synthetase |
| Content Type | Text |
| Resource Type | Article |
| Subject | Biochemistry Inorganic Chemistry |
