Transcription Activation by a Variety of AraC/XylS Family Activators Does Not Depend on the Class II-Specific Activation Determinant in the N-Terminal Domain of the RNA Polymerase Alpha Subunit

The N-terminal domain of the RNA polymerase alpha subunit (alpha-NTD) was tested for a role in transcription activation by a variety of AraC/XylS family members. Based on substitutions at residues 162 to 165 and an extensive genetic screen we conclude that alpha-NTD is not an activation target for these activators.