Protein Family Models

In the E. coli cytosol, a fraction of the newly synthesised proteins requires the activity of molecular chaperones for folding to the native state. The major chaperones implicated in this folding process are the ribosome-associated Trigger Factor (TF), and the DnaK and GroEL chaperones with their respective co-chaperones. Trigger Factor is an ATP-independent chaperone and displays chaperone and peptidyl-prolyl-cis-trans-isomerase (PPIase) activities in vitro. It is composed of at least three domains, an N-terminal domain which mediates association with the large ribosomal subunit, a central substrate binding and PPIase domain with homology to FKBP proteins, and a C-terminal domain of unknown function. The positioning of TF at the peptide exit channel, together with its ability to interact with nascent chains as short as 57 residues renders TF a prime candidate for being the first chaperone that binds to the nascent polypeptide chains [1]. This family represents the N-terminal region of the protein. [1]. 12603737. Trigger Factor and DnaK possess overlapping substrate pools and binding specificities. Deuerling E, Patzelt H, Vorderwulbecke S, Rauch T, Kramer G, Schaffitzel E, Mogk A, Schulze-Specking A, Langen H, Bukau B;. Mol Microbiol 2003;47:1317-1328. (from Pfam)

Date:

2024-10-16

trigger factor functions as a peptidylprolyl isomerase that is involved in protein export and acts as a chaperone by maintaining the newly synthesized protein in an open conformation

Date:

2024-05-07

Trigger factor is a ribosome-associated molecular chaperone and is the first chaperone to interact with nascent polypeptide. Trigger factor can bind at the same time as the signal recognition particle (SRP), but is excluded by the SRP receptor (FtsY). The central domain of trigger factor has peptidyl-prolyl cis/trans isomerase activity. This protein is found in a single copy in virtually every bacterial genome.

Gene:

tig

Date:

2024-06-12