Figure 6. Canonical class A and class B members form interclass J-protein networks in eukaryotic cells.
Cytosolic yeast and human canonical class A and class B members (e.g. Ydj1 and Sis1, Saccharomyces cerevisiae; DNAJA2 and DNAJB1, Homo sapiens) form interclass J-protein complexes via complementary binding interfaces at the JDs and the hinge regions of CTDs. E. coli cytosol contains only a single pair of canonical class A (DnaJ) and class B (CbpA) J-proteins. These bacterial J-proteins however fail to form interclass J-protein complexes due to the lack of complementary structural features required to establish intermolecular JD-CTD contacts.