Perturbed ATPase activity and not "close confinement" of substrate in the cis cavity affects rates of folding by tail-multiplied GroEL.

ABSTRACT: Folding of substrate proteins inside the sequestered and hydrophilic GroEL-GroES cis cavity favors production of the native state. Recent studies of GroEL molecules containing volume-occupying multiplications of the flexible C-terminal tail segments have been interpreted to indicate that close confinement of substrate proteins in the cavity optimizes the rate of folding: the rate of folding of a larger protein, Rubisco (51 kDa), was compromised by multiplication, whereas that of a smaller protein, rhodanese (33 kDa), was increased by tail duplication. Here, we report that this latter effect does not extend to the subunit of malate dehydrogenase (MDH), also 33 kDa. In addition, single-ring versions of tail-duplicated and triplicated molecules, comprising stable cis complexes, did not produc

SUBMITTER: Farr GW 

PROVIDER: S-EPMC1828711 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature