Source:
Generated By: https://synbiohub.org/public/igem/igem2sbol/1
Created by: Anna Stikane
Date created: 2014-09-18 11:00:00
Date modified: 2015-05-08 01:10:16
GFP (mut3b) with AAV-ssrA degradation tag
| Types | DnaRegion |
| Roles | Coding CDS |
| Sequences | BBa_K1399005_sequence (Version 1) |
Description
GFP (mut3b) (see part BBa_E0040) with added AAV-ssrA degradation tag (part BBa_I11012). The tag increases RFP turn-over rate, thus providing better temporal resolution of red fluorescence. In the same time, maximal fluorescence amplitudes will be lower as newly formed protein is degraded as soon as it is formed.The tag encodes peptide sequence AANDENYAAAV and is recognized by ClpA and ClpX unfoldases and ClpX mediator SspB.[1] ClpA and ClpX then form a proteosome-like complex with ClpP protease and the protein is degraded.[1]
The final three residues of the tag determines the strength of interaction with ClpX and thus the final protein degradation rate.[2] The AAV tag is reported to lead to reasonably fast protein degradation, degrading GFP with rate -0.012 per minute.[2] However, be aware that exact protein degradation rate depends on multiple factors: ClpXP and ClpAP protease and SspB mediator concentrations, protein stability, Km of binding to the protease, temperature [3].
References:
[1] Flynn, J. M. et al. Overlapping recognition determinants within the ssrA degradation tag allow modulation of proteolysis. Proc. Natl. Acad. Sci. U. S. A. 98, 10584???9 (2001).
[2] Andersen, J. B. et al. New unstable variants of green fluorescent protein for studies of transient gene expression in bacteria. Appl. Environ. Microbiol. 64, 2240???6 (1998).
[3] Purcell, O., Grierson, C. S., Bernardo, M. Di & Savery, N. J. Temperature dependence of ssrA-tag mediated protein degradation. J. Biol. Eng. 6, 10 (2012).
Notes
The tag was attached to RFP using PCR and MABEL (mutagenesis with blunt-end ligation), thus avoiding introduction of additonal residues and restriction site. Different parts of the tag are recognized by different proteins, for example, the final 3 residues (AAV in this case) are recognised by ClpX, whereas first 4 residues of the tag are required for efficient SspB binding.[1] Thus modifications of these critical residues alter the efficacy with what different proteases bind to it.Source
GFP comes from part BBa_E0040, tag sequence was obtained from part I11012, but same tag was also used in paper by Andersen et al., (1998).[2]| Sequence Annotation | Location | Component / Role(s) |
| start GFP (mut3b) AAV-ssrA tag stop stop | 1,3 4,714 715,747 748,750 751,753 | feature/start start_codon feature/cds CDS tag feature/tag stop_codon feature/stop stop_codon feature/stop |