Lattice Model Simulations of Polypeptide Chain Folding

A recently developed 1.4 nm gold cluster has been found to be useful in labeling macromolecular sites to 1-3 nm resolution. The gold compound is organically derivatized to contain a monofunctional arm for covalent linking to biomolecules. This may be used to mark a specific site on a structure, or to first label a component and then reassemble a multicomponent macromolecular complex. Two examples are given here: the chaperonin groEL and ribosomes.Chaperonins are essential oligomeric complexes that mediate nascent polypeptide chain folding to produce active proteins. The E. coli chaperonin, groEL, has two stacked rings with a central hole ∽6 nm in diameter. The protein dihydrofolate reductase (DHFR) is a small protein that has been used in chain folding experiments, and serves as a model substrate for groEL. By labeling the DHFR with gold, its position with respect to the groEL complex can be followed. In particular, it was sought to determine if DHFR refolds on the external surface of the groEL complex, or whether it interacts in the central cavity.

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The 2.8-A resolution structure of the L-arabinose-binding protein from Escherichia coli. Polypeptide chain folding, domain similarity, and probable location of sugar-binding site.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)40168-2 ◽

1977 ◽

Vol 252 (14) ◽

pp. 5142-5149 ◽

Cited By ~ 22

Author(s):

F A Quiocho ◽

G L Gilliland ◽

G N Phillips

Keyword(s):

Escherichia Coli ◽

Binding Site ◽

Polypeptide Chain ◽

Binding Protein ◽

Chain Folding ◽

Sugar Binding ◽

Domain Similarity ◽

Resolution Structure

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Protein folding in the cell: functions of two families of molecular chaperone, hsp 60 and TF55-TCP1

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1993.0030 ◽

1993 ◽

Vol 339 (1289) ◽

pp. 313-326 ◽

Cited By ~ 90

Keyword(s):

Protein Folding ◽

Mechanism Of Action ◽

Molecular Chaperone ◽

Polypeptide Chain ◽

Family Members ◽

Chain Folding ◽

Cell Functions ◽

Cellular Compartments

Two families of molecular chaperone, the hsp 60-GroEL family and the TF55-TCP1 family, have been discovered in evolutionarily related cellular compartments. A member of one of these families, hsp 60, has been shown to play a global role in polypeptide chain folding in mitochondria. We review here studies of both hsp 60 and other family members, discussing their essential physiological roles and mechanism of action.

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