Zinc-Responsive Regulation of Alternative Ribosomal Protein Genes in Streptomyces coelicolor Involves Zur and R
| Autor: | Ben Pascoe, Dimitris Kallifidas, Gillian A. Owen, Mark S. B. Paget |
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| Rok vydání: | 2007 |
| Předmět: |
Ribosomal Proteins
Transcription Genetic Operon Molecular Sequence Data chemistry.chemical_element Electrophoretic Mobility Shift Assay Sigma Factor Streptomyces coelicolor Zinc Plasma protein binding Biology Microbiology Bacterial Proteins Ribosomal protein Sigma factor Gene Regulation Promoter Regions Genetic Molecular Biology Gene Genetics Base Sequence Gene Expression Regulation Bacterial biology.organism_classification chemistry Biochemistry Mutation Cysteine Protein Binding |
| Popis: | Streptomyces coelicolor contains paralogous versions of seven ribosomal proteins (S14, S18, L28, L31, L32, L33, and L36), which differ in their potential to bind structural zinc. The paralogues are termed C + or C − on the basis of the presence or absence of putative cysteine ligands. Here, mutational studies suggest that the C − version of L31 can functionally replace its C + paralogue only when expressed at an artificially elevated level. We show that the level of expression of four transcriptional units encoding C − proteins is elevated under conditions of zinc deprivation. Zur controls the expression of three transcriptional units (including rpmG2 , rpmE2 , rpmB2 , rpsN2 , rpmF2 , and possibly rpsR2 ). Zur also controls the expression of the znuACB operon, which is predicted to encode a high-affinity zinc transport system. Surprisingly, the zinc-responsive control of the rpmG3-rpmJ2 operon is dictated by σ R , a sigma factor that was previously shown to control the response to disulfide stress in S. coelicolor . The induction of σ R activity during zinc limitation establishes an important link between thiol-disulfide metabolism and zinc homeostasis. |
| Databáze: | OpenAIRE |
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