Specificity of localization and phosphotransfer in the CheA proteins ofRhodobacter sphaeroides
| Autor: | Jennifer Hill, Judith P. Armitage, Rebecca Hamer, David A. Wilkinson, Kathryn A. Scott, Steven L. Porter, Eleanor A.L. Bagg |
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| Rok vydání: | 2010 |
| Předmět: |
Models
Molecular Cytoplasm Histidine Kinase Molecular Sequence Data Sequence alignment Rhodobacter sphaeroides Models Biological Microbiology Substrate Specificity Bacterial Proteins Amino Acid Sequence Phosphorylation Molecular Biology Peptide sequence biology Chemotaxis Cell Membrane Histidine kinase DNA Shuffling biology.organism_classification Protein Structure Tertiary Biochemistry bacteria biological phenomena cell phenomena and immunity Signal transduction Chemosensory clusters Protein Kinases Sequence Alignment |
| Zdroj: | Molecular Microbiology. 76:318-330 |
| ISSN: | 1365-2958 0950-382X |
| Popis: | Specificity of protein-protein interactions plays a vital role in signal transduction. The chemosensory pathway of Rhodobacter sphaeroides comprises multiple homologues of chemotaxis proteins characterized in organisms such as Escherichia coli. Three CheA homologues are essential for chemotaxis in R. sphaeroides under laboratory conditions. These CheAs are differentially localized to two chemosensory clusters, one at the cell pole and one in the cytoplasm. The polar CheA, CheA(2), has the same domain structure as E. coli CheA and can phosphorylate all R. sphaeroides chemotaxis response regulators. CheA(3) and CheA(4) independently localize to the cytoplasmic cluster; each protein has a subset of the CheA domains, with CheA(3) phosphorylating CheA(4) together making a functional CheA protein. Interestingly, CheA(3)-P can only phosphorylate two response regulators, CheY(6) and CheB(2). R. sphaeroides CheAs exhibit two interesting differences in specificity: (i) the response regulators that they phosphorylate and (ii) the chemosensory cluster to which they localize. Using a domain-swapping approach we investigated the role of the P1 and P5 CheA domains in determining these specificities. We show that the P1 domain is sufficient to determine which response regulators will be phosphorylated in vitro while the P5 domain is sufficient to localize the CheAs to a specific chemosensory cluster. |
| Databáze: | OpenAIRE |
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