4pko: Difference between revisions
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<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4pko FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4pko OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4pko RCSB], [http://www.ebi.ac.uk/pdbsum/4pko PDBsum]</span></td></tr> | <tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4pko FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4pko OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4pko RCSB], [http://www.ebi.ac.uk/pdbsum/4pko PDBsum]</span></td></tr> | ||
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== Publication Abstract from PubMed == | |||
The GroE chaperonins assist substrate protein (SP) folding by cycling through several conformational states. With each cycle the SP is, in turn, captured, unfolded, briefly encapsulated (t1/2 approximately 1 s), and released by the chaperonin complex. The protein-folding functional form is the US-football-shaped GroEL:GroES2 complex. We report structures of two such "football" complexes to approximately 3.7-A resolution; one is empty whereas the other contains encapsulated SP in both chambers. Although encapsulated SP is not visible on the electron density map, using calibrated FRET and order-of-addition experiments we show that owing to SP-catalyzed ADP/ATP exchange both chambers of the football complex encapsulate SP efficiently only if the binding of SP precedes that of ATP. The two rings of GroEL thus behave as a parallel processing machine, rather than functioning alternately. Compared with the bullet-shaped GroEL:GroES1 complex, the GroEL:GroES2 football complex differs conformationally at the GroEL-GroES interface and also at the interface between the two GroEL rings. We propose that the electrostatic interactions between the epsilon-NH3+ of K105 of helix D in one ring with the negatively charged carboxyl oxygen of A109 at the carboxyl end of helix D of the other ring provide the structural basis for negative inter-ring cooperativity. | |||
Formation and structures of GroEL:GroES2 chaperonin footballs, the protein-folding functional form.,Fei X, Ye X, LaRonde NA, Lorimer GH Proc Natl Acad Sci U S A. 2014 Aug 18. pii: 201412922. PMID:25136110<ref>PMID:25136110</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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== References == | |||
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