Chaperonin complex with a newly folded protein encapsulated in the folding chamber. Export

@article{citeulike:3840189, abstract = {A subset of essential cellular proteins requires the assistance of chaperonins (in Escherichia coli, GroEL and GroES), double-ring complexes in which the two rings act alternately to bind, encapsulate and fold a wide range of nascent or stress-denatured proteins. This process starts by the trapping of a substrate protein on hydrophobic surfaces in the central cavity of a GroEL ring. Then, binding of ATP and co-chaperonin GroES to that ring ejects the non-native protein from its binding sites, through forced unfolding or other major conformational changes, and encloses it in a hydrophilic chamber for folding. ATP hydrolysis and subsequent ATP binding to the opposite ring trigger dissociation of the chamber and release of the substrate protein. The bacteriophage T4 requires its own version of GroES, gp31, which forms a taller folding chamber, to fold the major viral capsid protein gp23 (refs 16-20). Polypeptides are known to fold inside the chaperonin complex, but the conformation of an encapsulated protein has not previously been visualized. Here we present structures of gp23-chaperonin complexes, showing both the initial captured state and the final, close-to-native state with gp23 encapsulated in the folding chamber. Although the chamber is expanded, it is still barely large enough to contain the elongated gp23 monomer, explaining why the GroEL-GroES complex is not able to fold gp23 and showing how the chaperonin structure distorts to enclose a large, physiological substrate protein.}, author = {Clare, D. K. and Bakkes, P. J. and van Heerikhuizen, H. and van der Vies, S. M. and Saibil, H. R.}, citeulike-article-id = {3840189}, citeulike-linkout-0 = {http://dx.doi.org/10.1038/nature07479}, citeulike-linkout-1 = {http://dx.doi.org/10.1038/nature07479}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/19122642}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=19122642}, day = {1}, doi = {10.1038/nature07479}, issn = {1476-4687}, journal = {Nature}, keywords = {chaperonin, em, experiment, protein, structure}, month = {January}, number = {7225}, pages = {107--110}, posted-at = {2009-01-19 08:22:09}, priority = {2}, publisher = {Macmillan Publishers Limited. All rights reserved}, title = {Chaperonin complex with a newly folded protein encapsulated in the folding chamber.}, url = {http://dx.doi.org/10.1038/nature07479}, volume = {457}, year = {2009} }

TY - JOUR ID - citeulike:3840189 L3 - citeulike-article-id:3840189 N2 - A subset of essential cellular proteins requires the assistance of chaperonins (in Escherichia coli, GroEL and GroES), double-ring complexes in which the two rings act alternately to bind, encapsulate and fold a wide range of nascent or stress-denatured proteins. This process starts by the trapping of a substrate protein on hydrophobic surfaces in the central cavity of a GroEL ring. Then, binding of ATP and co-chaperonin GroES to that ring ejects the non-native protein from its binding sites, through forced unfolding or other major conformational changes, and encloses it in a hydrophilic chamber for folding. ATP hydrolysis and subsequent ATP binding to the opposite ring trigger dissociation of the chamber and release of the substrate protein. The bacteriophage T4 requires its own version of GroES, gp31, which forms a taller folding chamber, to fold the major viral capsid protein gp23 (refs 16-20). Polypeptides are known to fold inside the chaperonin complex, but the conformation of an encapsulated protein has not previously been visualized. Here we present structures of gp23-chaperonin complexes, showing both the initial captured state and the final, close-to-native state with gp23 encapsulated in the folding chamber. Although the chamber is expanded, it is still barely large enough to contain the elongated gp23 monomer, explaining why the GroEL-GroES complex is not able to fold gp23 and showing how the chaperonin structure distorts to enclose a large, physiological substrate protein. IS - 7225 JF - Nature SN - 1476-4687 EP - 110 TI - Chaperonin complex with a newly folded protein encapsulated in the folding chamber. PB - Macmillan Publishers Limited. All rights reserved VL - 457 SP - 107 KW - chaperonin KW - em KW - experiment KW - protein KW - structure AU - Clare, DK AU - Bakkes, PJ AU - van Heerikhuizen, H AU - van der Vies, SM AU - Saibil, HR PY - 2009/01/01/ UR - http://dx.doi.org/10.1038/nature07479 ER -