Characterization of the intergenic region which regulates the MspI restriction-modification system.
The 110-bp intergenic region between mspIM and mspIR, the genes encoding the MspI modification (M.MspI) and restriction (R.MspI) enzymes, respectively, was fused, in both orientations, with lacZ. Expression of a single-copy mspIM-lacZ fusion is more than 400-fold stronger than expression of an mspIR-lacZ fusion. M.MspI in trans represses expression of the mspIM-lacZ fusion by binding to the DNA but does not affect expression of the mspIR-lacZ fusion. Transcription start sites of the genes were identified, and a set of nonoverlapping promoters was assigned. DNase I footprinting showed that M.MspI binds to a site within the intergenic region that includes only the mspIM regulatory elements.
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Department of Pharmacology, State University of New York Health Science Center, Brooklyn 11203, USA.
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D018983:DNA Footprinting; D015257:DNA-Cytosine Methylases / Q000096:biosynthesis / Q000235:genetics*; D019003:Deoxyribonuclease HpaII / Q000096:biosynthesis / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014158:Transcription, Genetic
D011993:Recombinant Fusion Proteins; C029641:DNA modification methylase HpaII; D015257:DNA-Cytosine Methylases; D019003:Deoxyribonuclease HpaII