Vitamin B12 repression of the btuB gene in Salmonella typhimurium is mediated via a translational control which requires leader and coding sequences
| ISSN: |
1365-2958
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|---|---|
| Source: |
Blackwell Publishing Journal Backfiles 1879-2005
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| Topics: |
Biology
Medicine
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| Notes: |
lacZ transcriptional and translational fusions of various lengths showed that the control was exerted mainly at the translational level and required both coding and leader sequences in the btuB transcript. Regulatory mutants with a B12 non-repressible phenotype were isolated and the mutations were shown to be located at several sites within the btuB leader. Analysis of constructs carrying site-directed point mutations, which either destabilized or restabilized a putative RNA hairpin that sequesters the btuB ribosomal binding site, demonstrated that this hairpin was essential for normal repression. Comparison of the S. typhimurium btuB gene with the previously characterized S. typhimurium cbiA and Escherichia coli btuB genes reveals significant similarities as well as differences in the cis-acting sequences required for repression.
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| Type of Medium: |
Electronic Resource
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| URL: |