Part:BBa_K3143001
Doc toxin
Toxic component of a type II toxin-antitoxin (TA) system. Overexpression of Doc results in inhibition of growth in liquid cultures and a decrease in colony formation by inhibiting translation, stabilizing mRNA and polysomes; these effects are overcome by concomitant expression of antitoxin phd. Doc binds 70S ribosomes and the 30S ribosomal subunits, the binding site is the same as for the antibiotic hygromycin B[1]. The phd/doc family is one the smallest families of toxin–antitoxin modules and was first discovered as a plasmid addiction module on E.coli bacteriophage P1. phd and doc proteins function in unison to stabilize plasmid number by inducing a lethal response to P1 plasmid prophage loss.[2] See Phd antitoxin BBa_K3143002.
Characterization
We tested the effects of Phd-Doc. We used different inducible promoters to control the expression of Phd and Doc proteins, respectively. As can be seen from Fig 1, bacterial growth was completely inhibited after induction of Doc protein expression. When both Phd and Doc proteins are expressed, the growth of bacteria is no longer affected by Doc toxic proteins.
Figure 1: A The process for bacteria growth imaging B The imaging of bacteria growth of different groups after 24 hours
Reference
1. Liu M, Zhang Y, Inouye M, et al. Bacterial addiction module toxin Doc inhibits translation elongation through its association with the 30S ribosomal subunit[J]. Proceedings of the National Academy of Sciences, 2008, 105(15): 5885-5890.
2. Lehnherr H, Maguin E, Jafri S, et al. Plasmid addiction genes of bacteriophage P1: doc, which causes cell death on curing of prophage, and phd, which prevents host death when prophage is retained[J]. Journal of molecular biology, 1993, 233(3): 414-428.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
| None |