| Autor: |
Jones, J. C., Duffy, J. W., Dohlman, H. G., Temple, B. R. S., Jones, A. M., Machius, M. |
| Jazyk: |
angličtina |
| Rok vydání: |
2011 |
| DOI: |
10.17615/d7ej-tj93 |
| Popis: |
In animals, heterotrimeric guanine nucleotide–binding protein (G protein) signaling is initiated by G protein–coupled receptors (GPCRs), which activate G protein α subunits; however, the plant Arabidopsis thaliana lacks canonical GPCRs, and its G protein α subunit (AtGPA1) is self-activating. To investigate how AtGPA1 becomes activated, we determined its crystal structure. AtGPA1 is structurally similar to animal G protein α subunits, but our crystallographic and biophysical studies revealed that it had distinct properties. Notably, the helical domain of AtGPA1 displayed pronounced intrinsic disorder and a tendency to disengage from the Ras domain of the protein. Domain substitution experiments showed that the helical domain of AtGPA1 was necessary for self-activation and sufficient to confer self-activation to an animal G protein α subunit. These findings reveal the structural basis for a mechanism for G protein activation in Arabidopsis that is distinct from the well-established mechanism found in animals. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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