First Advisor

Rachel A. Hellmann-Whitaker


The family of aminoacyl-tRNA synthetases (aaRSs) ensures the fidelity of translation through providing a pool of correctly aminoacylated tRNA products that become incorporated by the ribosome. Leucyl-tRNA synthetase (LeuRS) has two functionally separate domains, one is the aminoacylation domain and the other is the CP1 editing domain. LeuRS can aminoacylate noncognate amino acids, therefore it relies on the CP1 editing domain to hydrolyze misaminoacylated tRNA products before they are released from the enzyme. The LeuRS enzyme must undergo a structural transition state in its reaction cycle in order to translocate the 3' acceptor stem of tRNA 30 Å from the aminoacylation active site to the CP1 domain hydrolytic active site. The translocation event is difficult to study, but we believe that we have generated mutations within LeuRS that alter the translocation event of tRNA. The mutations that we have generated lead to bacterial death in Escherichia coli (E. coli). Circular dichorism experiments indicate that our mutations do not significantly alter the secondary structure of LeuRS. In vitro biochemical studies demonstrate that these mutations reduce the rates of aminoacylation and hydrolysis, while also displaying misaminoacylation activity. We attribute these biochemical findings to the resulting bacterial death that is caused by these mutations

Included in

Biochemistry Commons



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.