Bacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype.
Sigma-F, the first sporulation-specific transcription factor of Bacillus subtilis, is regulated by an anti-sigma factor SpoIIAB, which can also act as a protein kinase that phosphorylates the anti-anti-sigma factor SpoIIAA. The time course of phosphorylation reaction is biphasic, a fact that has bee...
| Main Authors: | , , , , |
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| פורמט: | Journal article |
| שפה: | English |
| יצא לאור: |
2001
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| _version_ | 1826265799999881216 |
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| author | Lee, C Clarkson, J Shu, J Campbell, I Yudkin, MD |
| author_facet | Lee, C Clarkson, J Shu, J Campbell, I Yudkin, MD |
| author_sort | Lee, C |
| collection | OXFORD |
| description | Sigma-F, the first sporulation-specific transcription factor of Bacillus subtilis, is regulated by an anti-sigma factor SpoIIAB, which can also act as a protein kinase that phosphorylates the anti-anti-sigma factor SpoIIAA. The time course of phosphorylation reaction is biphasic, a fact that has been interpreted in terms of a mechanism for sequestering SpoIIAB away from sigmaF and thus allowing activation of sigmaF when needed. Site-directed mutagenesis of SpoIIAA has allowed us to isolate two mutants that cannot activate sigmaF and which are therefore Spo-. The two mutant SpoIIAA proteins, SpoIIAAL61A and SpoIIAAL90A, are phosphorylated with linear kinetics; in addition they are less able to form the stable non-covalent complex that wild-type SpoIIAA makes with SpoIIAB in the presence of ADP. The phosphorylated form of SpoIIAAL90A was hydrolysed by the specific phosphatase SpoIIE at the same rate as wild-type SpoIIAA-P, but the rate of hydrolysis of SpoIIAAL61A-P was much slower. The secondary structure and the global fold of the mutant proteins were unchanged from the wild type. The results are interpreted in terms of a model for the wild type in which SpoIIAB, after phosphorylating SpoIIAA, is released in a form that is tightly bound to ADP and which then makes a ternary complex with an unreacted SpoIIAA. We propose that it is the inability to make this ternary complex that deprives the mutant cells of a means of keeping SpoIIAB from inhibiting sigmaF. |
| first_indexed | 2024-03-06T20:29:19Z |
| format | Journal article |
| id | oxford-uuid:30845b1e-0fe7-4602-8db0-eb203dda3e2b |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:29:19Z |
| publishDate | 2001 |
| record_format | dspace |
| spelling | oxford-uuid:30845b1e-0fe7-4602-8db0-eb203dda3e2b2022-03-26T13:01:53ZBacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:30845b1e-0fe7-4602-8db0-eb203dda3e2bEnglishSymplectic Elements at Oxford2001Lee, CClarkson, JShu, JCampbell, IYudkin, MDSigma-F, the first sporulation-specific transcription factor of Bacillus subtilis, is regulated by an anti-sigma factor SpoIIAB, which can also act as a protein kinase that phosphorylates the anti-anti-sigma factor SpoIIAA. The time course of phosphorylation reaction is biphasic, a fact that has been interpreted in terms of a mechanism for sequestering SpoIIAB away from sigmaF and thus allowing activation of sigmaF when needed. Site-directed mutagenesis of SpoIIAA has allowed us to isolate two mutants that cannot activate sigmaF and which are therefore Spo-. The two mutant SpoIIAA proteins, SpoIIAAL61A and SpoIIAAL90A, are phosphorylated with linear kinetics; in addition they are less able to form the stable non-covalent complex that wild-type SpoIIAA makes with SpoIIAB in the presence of ADP. The phosphorylated form of SpoIIAAL90A was hydrolysed by the specific phosphatase SpoIIE at the same rate as wild-type SpoIIAA-P, but the rate of hydrolysis of SpoIIAAL61A-P was much slower. The secondary structure and the global fold of the mutant proteins were unchanged from the wild type. The results are interpreted in terms of a model for the wild type in which SpoIIAB, after phosphorylating SpoIIAA, is released in a form that is tightly bound to ADP and which then makes a ternary complex with an unreacted SpoIIAA. We propose that it is the inability to make this ternary complex that deprives the mutant cells of a means of keeping SpoIIAB from inhibiting sigmaF. |
| spellingShingle | Lee, C Clarkson, J Shu, J Campbell, I Yudkin, MD Bacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype. |
| title | Bacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype. |
| title_full | Bacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype. |
| title_fullStr | Bacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype. |
| title_full_unstemmed | Bacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype. |
| title_short | Bacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype. |
| title_sort | bacillus subtilis mutations that alter the pathway of phosphorylation of the anti anti sigmaf factor spoiiaa lead to a spo phenotype |
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