title: The chaperone activity of trigger factor is distinct from its isomerase activity during co-expression with adenylate kinase in Escherichia coli.
abstract: To investigate the molecular chaperone function of trigger factor (TF) and its relationship with isomerase activity in vivo, the assisted folding of adenylate kinase (AK) by TF in Escherichia coli was examined by measuring the amounts of soluble AK produced during co-expression. When the mutant of chicken AK, P17G, is expressed in plasmid pBVAK, 95% of the protein is found in inclusion bodies. Co-expression of AK with TF was achieved using a plasmid pBVAT that allowed expression of TF and AK in the same plasmid under separate control. Co-expression with TF resulted in an increase in the amount of soluble AK, with a higher increase when TF was expressed at higher levels in the cell. Co-expression of AK with the two TF mutants, Y221G and F233Y, in which peptidyl-prolyl cis/trans isomerase activity was 1% of wild-type, gave the same results as wild-type TF. This provides in vivo evidence that the molecular chaperone activity of TF is distinct from its isomerase activity.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, 15 Datun Road, 100101, Beijing, PR China.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Li
authors.forename: C P
authors.initials: CP
authors.lastname: Liu
authors.forename: L Q
authors.initials: LQ
authors.lastname: Zhu
authors.forename: G Z
authors.initials: GZ
authors.lastname: Jing
authors.forename: J M
authors.initials: JM
authors.lastname: Zhou
mesh_terms: D000263:Adenylate Kinase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D005786:Gene Expression Regulation / Q000235:genetics* / Q000502:physiology; D007535:Isomerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D019696:Peptidylprolyl Isomerase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011487:Protein Conformation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D029968:Escherichia coli Proteins; D018832:Molecular Chaperones; D011994:Recombinant Proteins; D000263:Adenylate Kinase; D007535:Isomerases; C403324:trigger factor, E coli; D019696:Peptidylprolyl Isomerase