An autoinhibitory conformation of theBacillus subtilisspore coat protein SpoIVA prevents its premature ATP-independent aggregation
Autor: | Vivek Anantharaman, Kumaran S. Ramamurthi, L. Aravind, Scarlett Lee, Jean-Philippe Castaing, Geoffrey E. Ravilious |
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Rok vydání: | 2014 |
Předmět: |
Models
Molecular Conformational change Protein Conformation DNA Mutational Analysis Molecular Sequence Data Phosphatase Bacillus subtilis Microbiology Article chemistry.chemical_compound Adenosine Triphosphate Protein structure Bacterial Proteins ATP hydrolysis Genetics Amino Acid Sequence Cytoskeleton Molecular Biology Actin Spores Bacterial biology Hydrolysis biology.organism_classification Biochemistry chemistry Biophysics Protein Multimerization Sequence Alignment Adenosine triphosphate |
Zdroj: | FEMS Microbiology Letters. 358:145-153 |
ISSN: | 0378-1097 |
Popis: | Spores of Bacillus subtilis are dormant cell types that are formed when the bacterium encounters starvation conditions. Spores are encased in a shell, termed the coat, which is composed of approximately seventy different proteins and protects the spore’s genetic material from environmental insults. The structural component of the basement layer of the coat is an exceptional cytoskeletal protein, termed SpoIVA, which binds and hydrolyzes ATP. ATP hydrolysis is utilized to drive a conformational change in SpoIVA that leads to its irreversible self-assembly into a static polymer in vitro. Here, we characterize the middle domain of SpoIVA, the predicted secondary structure of which resembles the chemotaxis protein CheX but, unlike CheX, does not harbor residues required for phosphatase activity. Disruptions in this domain did not abolish ATP hydrolysis, but resulted in mislocalization of the protein and reduction in sporulation efficiency in vivo. In vitro, disruptions in this domain prevented the ATP hydrolysis-driven conformational change in SpoIVA required for polymerization and led to the aggregation of SpoIVA into particles that did not form filaments. We propose a model in which SpoIVA initially assumes a conformation in which it inhibits its own aggregation into particles, and that ATP hydrolysis remodels the protein so that it assumes a polymerization-competent conformation. |
Databáze: | OpenAIRE |
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