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Published on: October 14, 2011

Mutations reducing the activity of c17, a promoter of phage lambda formed by a tandem duplication

M A Mozola, D I Friedman, C L Crawford

    Proceedings of the National Academy of Sciences of the United States of America
    |March 1, 1979
    PubMed

    Insights

    Researchers identified four mutations in the phage lambda c17 promoter that decrease its activity. These mutations affect the critical "Pribnow Box" sequence, crucial for transcription initiation.

    Area of Science:

    • Molecular Biology
    • Genetics
    • Virology

    Background:

    • The phage lambda c17 promoter is not naturally occurring and arises from a tandem duplication.
    • This duplication generates a functional
    • Pribnow Box,
    • a conserved DNA sequence essential for promoter activity and transcription initiation.

    Purpose of the Study:

    • To isolate and characterize mutations affecting the activity of the phage lambda c17 promoter.
    • To investigate the role of the Pribnow Box sequence in promoter function.

    Main Methods:

    • Isolation of independently selected mutations (scs) in the c17 promoter region of phage lambda.
    • Sequence analysis of the c17 promoter duplications carrying the scs mutations.

    Main Results:

    • Four scs mutations were identified, all reducing or eliminating c17 promoter activity.
    • Three mutations involved single base-pair changes within highly conserved regions of the Pribnow Box.
    • One mutation represented a reversion to the wild-type sequence, indicating the loss of duplicated base pairs.

    Conclusions:

    • The Pribnow Box sequence is critical for phage lambda c17 promoter activity.
    • Specific base-pair alterations within the Pribnow Box can significantly impair or abolish promoter function.
    • The study provides insights into the structure-function relationship of bacterial promoters.

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