Structural highlights
Function
TIG_ECOLI Involved in protein export. Acts as a chaperone by maintaining the newly synthesized secretory and non-secretory proteins in an open conformation. Binds to nascent polypeptide chains via ribosomal protein L23 (PubMed:12226666). Functions as a peptidyl-prolyl cis-trans isomerase in vitro, this activity is dispensible in vivo for chaperone activity.[1] [2] [3]
Publication Abstract from PubMed
The chaperone Trigger Factor (TF) from Escherichia coli forms a dimer at cellular concentrations. While the monomer structure of TF is well known, the spatial arrangement of this dimeric chaperone storage form has remained unclear. Here, we determine its structure by a combination of high-resolution NMR spectroscopy and biophysical methods. TF forms a symmetric head-to-tail dimer, where the ribosome binding domain is in contact with the substrate binding domain, while the peptidyl-prolyl isomerase domain contributes only slightly to the dimer affinity. The dimer structure is highly dynamic, with the two ribosome binding domains populating a conformational ensemble in the center. These dynamics result from intermolecular in trans interactions of the TF client-binding site with the ribosome binding domain, which is conformationally frustrated in the absence of the ribosome. The avidity in the dimer structure explains how the dimeric state of TF can be monomerized also by weakly interacting clients.
The dynamic dimer structure of the chaperone Trigger Factor.,Morgado L, Burmann BM, Sharpe T, Mazur A, Hiller S Nat Commun. 2017 Dec 8;8(1):1992. doi: 10.1038/s41467-017-02196-7. PMID:29222465[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hesterkamp T, Hauser S, Lutcke H, Bukau B. Escherichia coli trigger factor is a prolyl isomerase that associates with nascent polypeptide chains. Proc Natl Acad Sci U S A. 1996 Apr 30;93(9):4437-41. PMID:8633085
- ↑ Valent QA, Kendall DA, High S, Kusters R, Oudega B, Luirink J. Early events in preprotein recognition in E. coli: interaction of SRP and trigger factor with nascent polypeptides. EMBO J. 1995 Nov 15;14(22):5494-505. PMID:8521806
- ↑ Genevaux P, Keppel F, Schwager F, Langendijk-Genevaux PS, Hartl FU, Georgopoulos C. In vivo analysis of the overlapping functions of DnaK and trigger factor. EMBO Rep. 2004 Feb;5(2):195-200. Epub 2004 Jan 9. PMID:14726952 doi:10.1038/sj.embor.7400067
- ↑ Morgado L, Burmann BM, Sharpe T, Mazur A, Hiller S. The dynamic dimer structure of the chaperone Trigger Factor. Nat Commun. 2017 Dec 8;8(1):1992. doi: 10.1038/s41467-017-02196-7. PMID:29222465 doi:http://dx.doi.org/10.1038/s41467-017-02196-7
