Calcium Binding and Stability of HopQ1 in Pseudomonas syringae
Author Information
Author(s): Giska Fabian, Wojciech Rymaszewski, Malgorzata Lichocka, Marcin Piechocki, Jakub Kwiatkowski, Jarosław Poznański, Magdalena Górecka, Magdalena Krzymowska
Primary Institution: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
Hypothesis
How do chaperone-independent effectors like HopQ1 achieve an appropriate conformation for secretion?
Conclusion
The study shows that the atypical calcium binding motif of HopQ1 regulates its thermal stability in a pH-dependent manner.
Supporting Evidence
- HopQ1 forms oligomers that depend on calcium binding.
- The stability of HopQ1 increases with pH and calcium concentration.
- Mutations that prevent calcium binding lead to reduced stability of HopQ1.
- FRET analysis indicates that HopQ1 can self-assemble in plant cells.
Takeaway
HopQ1, a protein from a plant pathogen, changes shape based on calcium levels and pH, helping it move into plant cells.
Methodology
The study used size exclusion chromatography, multi-angle light scattering, and fluorescence resonance energy transfer to analyze HopQ1.
Digital Object Identifier (DOI)
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