Structural highlights
Function
CH60_ECOLI Prevents misfolding and promotes the refolding and proper assembly of unfolded polypeptides generated under stress conditions.[HAMAP-Rule:MF_00600] Essential for the growth of the bacteria and the assembly of several bacteriophages. Also plays a role in coupling between replication of the F plasmid and cell division of the cell.[HAMAP-Rule:MF_00600]
Publication Abstract from PubMed
The bacterial chaperonin GroEL and its cofactor, GroES, form a nano-cage for a single molecule of substrate protein (SP) to fold in isolation. GroEL and GroES undergo an ATP-regulated interaction cycle to close and open the folding cage. GroEL consists of two heptameric rings stacked back to back. Here, we show that GroEL undergoes transient ring separation, resulting in ring exchange between complexes. Ring separation occurs upon ATP-binding to the trans ring of the asymmetric GroEL:7ADP:GroES complex in the presence or absence of SP and is a consequence of inter-ring negative allostery. We find that a GroEL mutant unable to perform ring separation is folding active but populates symmetric GroEL:GroES2 complexes, where both GroEL rings function simultaneously rather than sequentially. As a consequence, SP binding and release from the folding chamber is inefficient, and E. coli growth is impaired. We suggest that transient ring separation is an integral part of the chaperonin mechanism.
GroEL Ring Separation and Exchange in the Chaperonin Reaction.,Yan X, Shi Q, Bracher A, Milicic G, Singh AK, Hartl FU, Hayer-Hartl M Cell. 2017 Dec 26. pii: S0092-8674(17)31490-3. doi: 10.1016/j.cell.2017.12.010. PMID:29336887[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Yan X, Shi Q, Bracher A, Milicic G, Singh AK, Hartl FU, Hayer-Hartl M. GroEL Ring Separation and Exchange in the Chaperonin Reaction. Cell. 2017 Dec 26. pii: S0092-8674(17)31490-3. doi: 10.1016/j.cell.2017.12.010. PMID:29336887 doi:http://dx.doi.org/10.1016/j.cell.2017.12.010
