Mutations in the C-terminal fragment of DnaK affecting peptide binding

摘要: Abstract Escherichia coli DnaK acts as a molecular chaperone through its ATP-regulated binding and release of polypeptide substrates. Overexpressing C-terminal fragment (CTF) (Gly-384 to Lys-638) containing the substrate domain is lethal in wild-type E. coli. This dominant-negative phenotype may result from nonproductive CTF cellular targets DnaK. Mutations affecting were identified by selecting noncytotoxic mutants followed vitro screening. The clustering such mutations three-dimensional structure suggests model that loops L1,2 L4,5 form rigid core critical for interactions with substrate.