HSP40: Molecular Weight

HSP40 molecular weights range from 10 kDa (DnaJC19) to 254 kDa (DnaJC13) across the heterogeneous group of well-conserved proteins. Similarly, molecular masses of J-like proteins vary between 10 kDa (DnaJC24) and 520 kDa (DnaJC29/sacsin). Functional genes encoding DNAJ/HSP40 proteins map to human chromosomes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 19, 20, 21 and 22. It has been assumed that DNAJs/HSP40s are homodimeric proteins that reside in the cytosol of prokaryotes ⁹ and various subcellular compartments of eukaryotes as well as in the extracellular milieu (also see Localization).