4pkn

Crystal structure of the football-shaped GroEL-GroES2-(ADPBeFx)14 complex containing substrate Rubisco

spinqualitylabelsall models 4pkn, resolution 3.66Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4pkn is a 28 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.66Å Ligands: ADP, BEF, K, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q548M1_ECOLX Prevents misfolding and promotes the refolding and proper assembly of unfolded polypeptides generated under stress conditions (By similarity).[RuleBase:RU000419][HAMAP-Rule:MF_00600] 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Chaperonin 3D structures

Proteopedia Page Contributors and Editors (what is this?)

OCA