MntS helps activate the manganese-dependent RNR, NrdEF.

<p>Cells pre-cultured in anaerobic MOPS glucose/casamino acids medium were diluted into aerobic medium with or without 50 μM MnCl₂ at time zero; viability was monitored by anaerobic plating. “Import-minus” strains contain Δ<i>tonB</i> Δ<i>feoABC</i> Δ<i>zupT</i> null alleles and therefore have reduced iron import. The data are representative of at least three independent experiments. A. Strains were JEM609 (Import^-), JEM1181 (Import^- Δ<i>mntS</i>), JEM1136 (Import^- Δ<i>nrdAB</i>), JEM1836 (Import^- Δ<i>nrdAB</i> Δ<i>mntS</i>), and JEM722 (Import^- Δ<i>nrdAB</i> Δ<i>nrdHIEF</i>). B. Viability of Import^- Δ<i>nrdAB</i> Δ<i>mntS</i> (JEM1183) harboring empty vector (pACYC184) or pMntS2 (pLW131, <i>mntS</i> under the control of its native promoter).