Chaperonin subunits

Kim, S., K. R. Willison, and A. L. Horwich (1994). Cystosolic chaperonin subunits have a conserved ATPase domain but diverged polypeptide-binding domains. TrendsBiochem. Sci. 19, 543-548. 

Kubota, H., S. Yokota, H. Yanagi, and T. Yura (2000). Transcriptional regulation of the mouse cytosolic chaperonin subunit gene Ccta/Tcp-1 by Staf family zinc finger proteins./ Biol. Chem. 275, 28641-28648. 

Stoldt, V., F. Rademacher, V. Kehren, J. F. Ernst, D. A. Pearce, and F. Sherman (1996). Review The Cct eukaryotic chaperonin subunits of Saccharomyces cerevisiae and other yeasts. Yeast 12, 523-529. 

Expression of cpkA or cpkB from the T7 promoter has been achieved in the E. coli strain BL21 (DE3), which possesses a stable chromosomal copy of the T7 RNA polymerase gene under control of the lacUVS promoter. Both chaperonin subunits, CpkA and CpkB, have been purified in the same way. Details for CpkB purification are described below. 

Figure 6.11 Schematic diagram of the chaperonin GroEL molecule as a cylinder with 14 subunits arranged in two tings of 7 subunits each. The space occupied by one subunit is red and the hole inside the cylinder is blue.

E, and K which must be assembled in the correct sequence. A chaperonin PapD is also required as is an "usher protein," PapC,50 and also the disulfide exchange protein DsbA (Chapter 10). DsbA helps PapD to form the correct disulfide bridges as it folds and PapD binds and protects the various pilus subunits as they accumulate in the periplasmic space of the host. The usher protein displaces the chaperonin PapD and "escorts" the subunits into the membrane where the extrusion occurs.50 55... 

Jack bean urease is a trimer or hexamer of identical 91-kDa subunits while that of the bacterium Klebsiella has an (a(32y2)2 stoichiometry. Nevertheless, the enzymes are homologous and both contain the same binickel catalytic center (Fig. 16-25).435-4373 The three-dimensional structure of the Klebsiella enzyme revealed that the two nickel ions are bridged by a carbamyl group of a carbamylated lysine. Like ribulose bisphos-phate carboxylase (Fig. 13-10), urease also requires C02 for formation of the active enzyme.438 Formation of the metallocenter also requires four additional proteins, including a chaperonin and a nickel-binding protein.438 439... 

Tam S, Geller R, Spiess C, Frydman J (2006) The chaperonin TRiC controls polyglutamine aggregation and toxicity through subunit-specific interactions. Nat Cell Biol 8 1155-1162. 

Llorca, O., E. A. McCormack, G. Hynes, J. Grantham, J. Cordell, J. L. Carrascosa, K. R. Willison, J. J. Fernandez, and J. M. Valpuesta. 1999. Eukaryotic type II chaperonin CCT interacts with actin through specific subunits. Nature 402 693-6. 

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