title: Structural stability of E. coli trigger factor studied by synchrotron small-angle X-ray scattering.
abstract: Solution small-angle X-ray scattering (SAXS) is an effective technique for quantitatively measuring the compactness and shape of proteins. We use SAXS to study the structural characteristics and unfolding transitions induced by urea for full length Escherichia coli trigger factor (TF) and a series of truncation mutants, obtaining and comparing the radiuses of gyration (Rg), the distance-distribution function (P(r) function) and integrated intensity of TF variants in native and unfolding states. The C-terminal 72-residue truncated mutant TF360 exhibited dramatic structural differences and reduced stability compared with the whole TF molecule, while the N-domain truncated mutant MC maintained its compact structure with reduced stability. These results indicate that the C-terminal region of TF plays an important role in the structural and conformational stabilities of the TF molecule, while the N-domain is relatively independent.
authors.affiliation: Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road, Zhangjiang Hi-Tech Park, Pudong, Shanghai 201210, China. Electronic address: shiy@sari.ac.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Department of Physics, Kansai Medical University, 2-5-1, Shin-Machi, Hirakata 573-1010, Japan.
authors.forename: Masaji
authors.initials: M
authors.lastname: Shinjo
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Zhou
authors.affiliation: Department of Physics, Kansai Medical University, 2-5-1, Shin-Machi, Hirakata 573-1010, Japan. Electronic address: kiharah1234@gmail.com.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kihara
mesh_terms: D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016296:Mutagenesis; D019696:Peptidylprolyl Isomerase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D058767:Protein Unfolding; D053838:Scattering, Small Angle; D014508:Urea / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D029968:Escherichia coli Proteins; D014508:Urea; C403324:trigger factor, E coli; D019696:Peptidylprolyl Isomerase
keywords: C-terminal truncation; Folding; Small-angle X-ray scattering; Stability; Trigger factor