| Autor: |
Mello, L. V., Millner, P. A., Findlay, J. B. C. |
| Zdroj: |
Journal of Protein Chemistry; January 2002, Vol. 21 Issue: 1 p29-34, 6p |
| Abstrakt: |
Our previous studies using molecular dynamics have shown a hinge bending motion between the helical and the GTPase domains of GαT(Mello et al., 1998). The hypothesis that this motion is allowed by residues Gly56 and Gly179 and that this motion may affect the ligand exchange was tested in this work. Mutations of Gly 56 were carried out and the mutant proteins were expressed in Sf9 cells using the Baculovirusexpression system. The recombinant proteins were purified using Ni-NTA affinity chromatography. The results for the (GDP/GTP) exchange assays showed that G56S and double mutants (D55G/G56S) proteins differ significantly from the wild type and D55G mutant forms. The Kdvalues for GTPγS binding of those mutants have decreased by approximately 10-fold. No difference in the GTPase activity was detected for the mutants. Thus, the biochemical results obtained support the conclusions of the computational studies. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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