The DnaJ domain in recombinant RSP16 was dispensable for rescue of RSP16⁻ cells. (A) Coomassie protein gel showed the bacterial extract used for electroporation. Purified RSP16ΔDnaJ-his precipitated and, thus, was not suitable for the experiment. The extract was prepared from IPTG-induced bacteria expressing truncated RSP16 (RSP16ΔDnaJ-his), RSP16-his, and the control RSP11-his (dots) or pET28(a) vector only. The percentage of recombinant protein was based on digital quantification of the protein gel. (B) The table lists the protein concentration and the results obtained at 30 min and 2 h after electroporation. Extract containing RSP16, both with or without the DnaJ domain, restored swimming ability to some 12E8 cells. No swimmers were found in the negative controls. Cells were digitally recorded 2 h after electroporation. Randomly selected swimmers (numbers indicated in parentheses) were analyzed for velocity. (C and D) For clarity, the percentage of swimmers (asterisks in B) was plotted as a histogram (C), as was velocity of swimmers rescued by similar concentration of recombinant proteins (D). The RSP16ΔDnaJ-his group was slightly slower than the intact RSP16 group (error bars represent SD; P < 0.001).