Single Transmembrane Peptide DinQ Modulates Membrane-Dependent Activities
Figure 2
Expression pattern and transcription start of the dinQ/agrAB locus.
(A) Northern analysis of dinQ and agrAB transcripts. A riboprobe specific to either dinQ (upper panel) or agrAB (lower panel) was hybridized to a northern blot with total RNA extracted from strains lacking dinQ (BK4040), agrA (BK4042) or agrB (BK4043) and compared to wt (AB1157) before and after UV exposure. Five dinQ transcripts assigned dinQ-a, -b, -c, -d and -e were detected. (B) A [32P]-labeled primer specific to dinQ was used in a primer extension assay to determine transcription initiation sites of the various dinQ transcripts. The primer extension assays were performed on total RNA extracted from wt (AB1157) and mutant strains agrA (BK4042) and agrB (BK4043). The base annotated for transcription initiation is indicated with an asterisk (red) for each transcript. Three primer extension products were detected that correlated in size to dinQ-a, -b and -d from 3′ mapping and the northern blot in (A). (C) A [32P]-labeled primer specific to agrAB was used in a primer extension assay to determine transcription initiation sites of agrA and agrB. Total RNA from mutant strain agrB (BK4043) was used to localize agrA transcription start and total RNA from mutant strain agrA (BK4042) was used to localize agrB transcription initiation, due to the transcripts sequence complementarity. The base annotated for transcription initiation is indicated with an asterisk (red) for each transcript.