Protein Secretion in B. subtilis
For the development of our project, we had to research the protein secretion pathways in Bacillus subtilis. As a contribution for future iGEM teams, we present our review, so that others can benefit from it. The Bacillus subtilis bacteria have the ability to overproduce a wide range of industrial enzymes. To accomplish this, a thorough study of the unique characteristics of B.subtilis' native protein secretory pathway to the extracellular medium is required .
The general secretion (Sec) pathway is B. subtilis' principal protein transportation route across the cytoplasmic membrane. This pathway sends proteins to the cytoplasmic membrane for insertion into or translocation over it . In general, the Sec pathway is made up of Sec-dependent signal peptides that are followed by the moiety of mature proteins. In terms of overall structure, Sec signal peptides have a tripartite structure that includes a positively charged amino-terminal region, a hydrophobic core, and a polar carboxyl-terminal region that contains the signal peptidase recognition site . Sec-dependent secretion has two distinct pathways: co-translational and post-translocation .
Another pathway is the Tat, which varies from the Sec in that it may transport completely folded proteins with a conserved region containing the twin-arginine motif in the signal peptide sequences. This pathway allows proteins to be secreted that would otherwise be too rapidly and tightly folded in the cytoplasm to be compatible with the first secretion system presented .
- Anné, J., Economou, A. & Bernaerts, K. Protein Secretion in Gram-Positive Bacteria: From Multiple Pathways to Biotechnology. Curr. Top. Microbiol. Immunol. 404, 267–308 (2016).
- Chatzi, K. E., Sardis, M. F., Karamanou, S. & Economou, A. Breaking on through to the other side: protein export through the bacterial Sec system. Biochem. J. 449, 25–37 (2013).
- Rusch, S. L. & Kendall, D. A. Interactions That Drive Sec-Dependent Bacterial Protein Transport. Biochemistry 46, 9665–9673 (2007).
- Lee, P. A., Tullman-Ercek, D. & Georgiou, G. The Bacterial Twin-Arginine Translocation Pathway. Annu Rev Microbiol 60, 373–395 (2006).
- Radeck, Jara, et al. "The Bacillus BioBrick Box: generation and evaluation of essential genetic building blocks for standardized work with Bacillus subtilis." Journal of biological engineering 7.1 (2013): 1-17.
- Hu, Yangbo, et al. "Ribosomal binding site switching: an effective strategy for high-throughput cloning constructions." PloS one 7.11 (2012): e50142.
- Omotajo, Damilola, et al. "Distribution and diversity of ribosome binding sites in prokaryotic genomes." BMC genomics 16.1 (2015): 1-8.
- Tsien, Roger Y. "The green fluorescent protein." Annual review of biochemistry 67.1 (1998): 509-544.
- Phillips, Gregory J. "Green fluorescent protein–a bright idea for the study of bacterial protein localization." FEMS microbiology letters 204.1 (2001): 9-18.