Difference between revisions of "Part:BBa K4387997"

Latest revision as of 17:27, 9 October 2022

HlyA-tag obtained from the hemolysin A one-step secretion system

The hemolysin A secretion machinery is a one-step secretion system (T1SS), originally isolated from uropathogenic E. coli strains. [1] It comprises three main peptides, the inner membrane proteins HlyB and HlyD, and the outer membrane protein TolC. Together, these three proteins build a continuous channel through which originally the HlyA toxin is secreted in a one-step manner. Interestingly, the secretion signal is not found on the N-terminal site, instead it is found at the C-terminal end and the signal sequence is not removed during secretion. Scientists have identified the secretion signal and were able to secrete various proteins of different sizes with this secretion machinery. [1] The very last 50 amino acids have been identified to bind to HlyB (BBa_K4387999) and HlyD (BBa_K4387998), leading to a successful secretion. However, various lengths of HlyA fragments have been used to secrete the protein of interest, either containing the last 60 amino acids, or even longer fragments with 218 or, as shown with this part, 651 amino acids. [1]

Sequence and Features

References

• [1] Ruano-Gallego, D., Fraile, S., Gutierrez, C. et al. Screening and purification of nanobodies from E. coli culture supernatants using the hemolysin secretion system. Microb Cell Fact 18, 47 (2019). https://doi.org/10.1186/s12934-019-1094-0