TY - JOUR T1 - Triggering protein folding within the GroEL-GroES complex. AU - Madan,Damian, AU - Lin,Zong, AU - Rye,Hays S, Y1 - 2008/09/09/ PY - 2008/9/11/pubmed PY - 2009/1/8/medline PY - 2008/9/11/entrez SP - 32003 EP - 13 JF - The Journal of biological chemistry JO - J Biol Chem VL - 283 IS - 46 N2 - The folding of many proteins depends on the assistance of chaperonins like GroEL and GroES and involves the enclosure of substrate proteins inside an internal cavity that is formed when GroES binds to GroEL in the presence of ATP. Precisely how assembly of the GroEL-GroES complex leads to substrate protein encapsulation and folding remains poorly understood. Here we use a chemically modified mutant of GroEL (EL43Py) to uncouple substrate protein encapsulation from release and folding. Although EL43Py correctly initiates a substrate protein encapsulation reaction, this mutant stalls in an intermediate allosteric state of the GroEL ring, which is essential for both GroES binding and the forced unfolding of the substrate protein. This intermediate conformation of the GroEL ring possesses simultaneously high affinity for both GroES and non-native substrate protein, thus preventing escape of the substrate protein while GroES binding and substrate protein compaction takes place. Strikingly, assembly of the folding-active GroEL-GroES complex appears to involve a strategic delay in ATP hydrolysis that is coupled to disassembly of the old, ADP-bound GroEL-GroES complex on the opposite ring. SN - 0021-9258 UR - https://www.unboundmedicine.com/medline/citation/18782766/Triggering_protein_folding_within_the_GroEL_GroES_complex_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0021-9258(20)56944-5 DB - PRIME DP - Unbound Medicine ER -