Solubility of mtHsp70, mtHsp70-HscA chimeras, and
70ATPase. A, domain composition of chaperone
constructs. B, SDS-PAGE analysis of protein solubility upon
expression in E. coli. Molecular weight markers (lane 1),
Rosetta 2 E. coli lacking plasmids (lane 2), and cells
harboring plasmids for expressing full-length mtHsp70 (pHsp70, lanes
3–5), a chimera having an mtHsp70 ATPase domain and a HscA
peptide-binding domain (p70-A, lanes 6–8), a chimera having an
HscA ATPase domain and a mtHsp70 PBD (pA-70, lanes 9–11), and
the isolated mtHsp70 ATPase domain (pATPase, lanes 12–14). For
each sample, 15 μg of total protein from whole cells (T) is shown
as well as the soluble lysates (S) and pellets (P) derived
from a sample that contained 15 μg of protein before fractionation.