INACTIVATION OF /cap beta/-GALACTOSIDASE INDUCTION BY ULTRAVIOLET LIGHT
The ability of Escherichia coli to form BETA -galactosidasc (EC 3.2 I.23) is strongly inhibited (relative to total protein synthesis) by ultraviolet light if the bacteria are maintained in the same medium before and after irradiation. However, irradiation has a much smaller effect if the bacteria are transferred to a poorer medium after irradiation and before induction. High concentrations of inducer do not reverse the ultraviolet light inhibition. Ultraviolet light appears mainly to cause a catabolite repression of BETA - galactosidase formation, similar to action of P/sup 32/ decay or thymine starvation, and not to inactivate the structural gene for this enzyme. Ultraviolet light inactivation of BETA galactosidase induction is not an all or none phenomenon in each bacterium. Increasing doses of ultraviolet light progressively inactivate formation of the enzyme in an individual bacterium. In contrast, inactivation of galactoside permease induction is virtually complete in each damaged cell. A difference in ultraviolet light sensitivity before and after induction was noted. This is attributed to inactivation of galactoside permease, which is initially essential for BETA -galactosidase induction. After induction had commenced, inhibition of permease formation no longer reduced the ability of the bacteria to produce BETA -galactosidase. (auth)
- Research Organization:
- Princeton Univ., N.J.
- NSA Number:
- NSA-18-009845
- OSTI ID:
- 4072713
- Journal Information:
- Biochim. Biophys. Acta., Vol. Vol: 76; Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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