title: The 69 kDa Escherichia coli maltodextrin glucosidase does not get encapsulated underneath GroES and folds through trans mechanism during GroEL/GroES-assisted folding.
abstract: Escherichia coli chaperonin GroEL and GroES assist in folding of a wide variety of substrate proteins in the molecular mass range of approximately 50 kDa, using cis mechanism, but limited information is available on how they assist in folding of larger proteins. Considering that the central cavity of GroEL can accommodate a non-native protein of approximately 60 kDa, it is important to study the GroEL-GroES-assisted folding of substrate proteins that are large enough for cis encapsulation. In this study, we have reported the mechanism of GroEL/GroES-assisted in vivo and in vitro folding of a 69 kDa monomeric E. coli protein maltodextrin glucosidase (MalZ). Coexpression of GroEL and GroES in E. coli causes a 2-fold enhancement of exogenous MalZ activity in vivo. In vitro, GroEL and GroES in the presence of ATP give rise to a 7-fold enhancement in MalZ refolding. Neither GroEL nor single ring GroEL (SR1) in the presence or absence of ATP could enhance the in vitro folding of MalZ. GroES could not encapsulate GroEL-bound MalZ. All these experimental findings suggested that GroEL/GroES-assisted folding of MalZ followed trans mechanism, whereas denatured MalZ and GroES bound to the opposite rings of a GroEL molecule.
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Subhankar
authors.initials: S
authors.lastname: Paul
authors.forename: Chanpreet
authors.initials: C
authors.lastname: Singh
authors.forename: Saroj
authors.initials: S
authors.lastname: Mishra
authors.forename: Tapan K
authors.initials: TK
authors.lastname: Chaudhuri
mesh_terms: D018835:Chaperonin 10 / Q000378:metabolism*; D018834:Chaperonin 60 / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism*; D019791:Guanidine / Q000378:metabolism; D008970:Molecular Weight; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D018835:Chaperonin 10; D018834:Chaperonin 60; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D011134:Polysaccharides; D011994:Recombinant Proteins; C008315:maltodextrin; D006026:Glycoside Hydrolases; C071233:malZ protein, E coli; D019791:Guanidine