GTPase Activity Analysis of eRF3 in Euplotes octocarinatus

作者：Song Li; Dong Jun Li; Zhao Ya Qin; Chai Bao Feng; Liang Ai Hua^*

来源：Journal of Microbiology and Biotechnology, 2010, 20(9): 1283-1287.

DOI：10.4014/jmb.1004.04020

• Dissociation constants
• eRF3
• Euplotes octocarinatus
• GTPase
• kinetic parameter

In eukaryotes, eRF3 participates in translation termination and belongs to the superfamily of GTPases. In this work, the dissociation constants for nucleosides bound to Euplotes octocarinatus eRF3 in the presence and absence of eRF1a were determined using fluorescence spectra methods. Furthermore, a GTP hydrolyzing assay of eRF3 was carried out using an HPLC method, and the kinetic parameters for cri, hydrolysis by eRF3 were determined. Consistent with data from humans, the results showed that eRF1a promoted the binding of CUP to eRF3 and the GTP hydrolyzing activity of eRF3. However, in contrast to the lack of GTP binding in the absence of eRF1 in human eRF3, the E. octocarinatus eRF3 was able to bind CUP by itself. The nucleotide binding affinity of the E. octocarinatus eRF3 also differed from the human data. A structure model and amino acid sequence alignment of potential G domains indicated that these differences may be due to valine 317 and glutamate 452 displacing the conserved glycine and lysine involved in CUP binding.

• 出版日期2010-9
• 单位山西大学