The ArsR protein is a trans-acting regulatory protein

Authors

  • J. Wu,

    1. Department of Biochemistry, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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  • B. P. Rosen

    Corresponding author
    1. Department of Biochemistry, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
    • *For correspon-dence Tel. (313) 577 1512; Fax (313) 577 2765.

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Summary

The arsR gene encodes the regulatory protein of the plasmid-encoded arsenical resistance operon. A series of in-frame fusions was constructed between the C-terminally truncated arsR gene and the coding region for the mature form of β-lactamase (blaM). Fusions containing most of the arsR gene were still inducible by arsenicals. Fusions containing less than 102 residues of the 117-residue ArsR protein were constitutive. When a wild-type arsR gene was placed in trans, the constitutive constructs were again inducible. The results demonstrate that the ArsR protein is a trans-acting regulatory protein which controls its own expression.

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