title: C-terminal 13-residue truncation induces compact trigger factor conformation and severely impairs its dimerization ability.
abstract: Trigger factor (TF) is the first chaperone to interact with nascent chains and facilitate their folding within bacteria. TF possesses a three-state equilibrium in vivo: monomeric TF bound to ribosome, free monomeric, and dimeric TF in cytoplasm. TF consists of an N-terminal ribosome binding domain, a middle peptidyl-prolyl cis/trans isomerase (PPIase) domain and a C-terminal domain involved in substrate binding and dimerization. Investigation of the effect of C-terminal 13 region on TF structure and function will help to further the understanding of its mechanism as a chaperone in vitro and in vivo. Here we present TF419, a TF mutant from which the C-terminal 13 residues were deleted to investigate the role of these residues in the structure stability and function of intact molecules. Small angle X-ray scattering (SAXS), fluorescence measurements and limited proteolysis results suggested that TF transitioned to a compact conformation when the Cterminal 13 residues were truncated. Further biochemical results reveal that TF dimerization was decreased as a result of the truncation. These results suggested that the C-terminal 13 residues play an important role in structural stability and chaperone function of TF.
authors.forename: Yi
authors.initials: Y
authors.lastname: Shi
authors.forename: Ling
authors.initials: L
authors.lastname: Yu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kihara
authors.affiliation: Shanghai Advanced Research Institute, Chinese Academy of Sciences, No.99, Haike Road, Zhangjiang Hi-Tech Park, Pudong, Shanghai, 201210, China. shiy@sari.ac.cn.
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Zhou
mesh_terms: D000595:Amino Acid Sequence; D002918:Chymotrypsin / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D019696:Peptidylprolyl Isomerase / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D011487:Protein Conformation; D055503:Protein Multimerization; D053838:Scattering, Small Angle; D017384:Sequence Deletion; D014961:X-Ray Diffraction
chemical_list: D029968:Escherichia coli Proteins; D002918:Chymotrypsin; C117608:alpha-chymotrypsin; C403324:trigger factor, E coli; D019696:Peptidylprolyl Isomerase