Part:BBa_K566008
Mnt repressor optimized for E. coli
Mnt repressor optimized from part BBa_C0072 with preferential codon usage for improved expression in E. coli. It acts on pMnt promoter (BBa_R0073).
Usage and Biology
Mnt contains 82 amino acids residues and is a tetramer in solution. It is encoded by the immI region of Salmonella phage P22 involved in the maintenance of lysogeny or the commitment to lytic growth. It also ecodes for the Ant protein and Arc repressor. Ant induces lytic growth of the prophage. During lysogenic growth Mnt represses expression of Ant from the prophage, this allows the lysogen to be stably maintained. Rightward transcription of the arc and ant genes initiates at Pant and can be negatively regulated by either Mnt or Arc. Transcription of mnt initiates at Pmnt and proceeds to the left. The Pant and Pmnt promoters overlap physically and compete for RNA polymerase. The Mnt operator site overlaps the -35 region of Pmnt and the startpoint of Pant transcription (Figure 1). Figure 2 shows the effect of Mnt concentration on run-off transcripts initiated at these two promoters. As the Mnt concentration is raised, transcription from Pant is repressed, whereas transcription from Pmnt, is stimulated. The stimulation of Pmnt transcription by Mnt corresponds to an approximate sixfold increase over basal transcription. In the absence of Mnt protein, the Pant promoter is much stronger than the Pmnt promoter.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21INCOMPATIBLE WITH RFC[21]Illegal BglII site found at 228
- 23COMPATIBLE WITH RFC[23]
- 25INCOMPATIBLE WITH RFC[25]Illegal AgeI site found at 148
- 1000COMPATIBLE WITH RFC[1000]
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