(E Detection of steady-state conversions of endogenous MgtE by YqgP variants bearing single-point mutations in putative Mn-binding region (BS184; 187; 196-203, Table EV2), cultivated in modified M9 minimal medium supplemented by low (1 μM) or high (100 μM) MnCl2. Black arrow marks full-length MgtE, and red arrow marks its N-terminal cleavage product by YqgP. 