Fig. 3.

ClpB is required for propagation of Ch SSB cPrD aggregates. (A) The frequency of dark blue colonies generated from plating the indicated clpB⁺ and ΔclpB starter cultures is shown. All starter cultures contained the Ch SSB cPrD vector, and either pSC101^TS–NEW1 (white bars) or pSC101^TS–NEW1–clpB (gray bars). After overnight growth at the permissive temperature, cultures were plated at a nonpermissive temperature to cure cells of pSC101^TS–NEW1 or pSC101^TS–NEW1–clpB. The sample-size weighted mean percentage of dark blue colonies from three independent experiments is shown with error bars indicating the SEM. (B) Colonies were generated by plating the indicated starter cultures at a temperature nonpermissive for pSC101^TS–NEW1 or pSC101^TS–NEW1–clpB replication. Cell extracts were prepared by pooling and lysing ∼700 scraped colonies for each starter culture from a single experiment. SDS-stable aggregates of Ch SSB cPrD fusion protein are not detected in ΔclpB colony scrapes, regardless of whether or not clpB was supplied during starter culture growth. The α-His antibody recognizes the His_6x–mYFP–Ch SSB cPrD fusion protein. See also SI Appendix, Fig. S4.