Functional Dissection of Escherichia coli Trigger Factor: Unraveling the Function of Individual Domains

• DOI: 10.1128/jb.186.12.3777-3784.2004
• Publication Date: 2004-06-02T18:59:14Z
• Authors: G. Kramer; A. Rutkowska; R. D. Wegrzyn; H. Patzelt; T. A. Kurz; F. Merz; T. Rauch; S. Vorderwülbecke; E. Deuerling; B. Bukau
• Keywords: Chaperone (clinical); Glyceraldehyde 3-phosphate dehydrogenase

ABSTRACT In Escherichia coli , the ribosome-associated chaperone Trigger Factor (TF) promotes folding of newly synthesized cytosolic proteins. TF is composed three domains: an N-terminal domain (N), which mediates ribosome binding; a central (P), has peptidyl-prolyl cis/trans isomerase activity and involved in substrate binding vitro; C-terminal (C) with unknown function. We investigated contributions individual domains (N, P, C) or combinations (NP, PC, NC) to vivo vitro. All fragments comprising N NP, complemented synthetic lethality Δ tig dnaK cells lacking DnaK, prevented protein aggregation these cells, cross-linked nascent polypeptides However, expressing alone grew more slowly showed less viability than synthesizing either NC, full-length TF, indicating beneficial P C TF's activity. vitro system purified components, none assisted refolding denatured d -glyceraldehyde-3-phosphate dehydrogenase manner comparable that wild-type suggesting observed dependent on their localization at ribosome. These results indicate domain, addition its function promote ribosome, per se sufficient substitute for vivo.