Trp-RNA Binding Attenuation Protein (TRAP)
Many bacteria regulate their production of L-Tryptophan (Trp) by a process called attenuation. When Trp is in abundance it would be inefficient to continue production, hence bacteria have evolved a Trp-concentration dependent regulatory mechanism for its synthesis. This mechanism is coordinated by a circular homo-oligomer protein (of 11 or 12 subunits) named Trp RNA-binding Attenuation protein (TRAP), the structure of which was solved in our group (Antson et al., Nature, 1999). In the presence of Trp, TRAP-Trp complex bind RNA and blocks transcription of the trp operon by forming a terminator stem-loop. In the reverse case, an anti-terminator loop is formed and transcription may proceed.
We have solved the structure of the anti-TRAP protein (AT). If uncharged tRNA-Trp levels become high, synthesis of an anti-TRAP protein is increased which forms a complex with TRAP, inhibiting its termination activity. In this line of work we engineered TRAP to alter its oligomeric state (subunit number) and thermal stability.
- Antson AA, Dodson EJ, Dodson G, Greaves RB, Chen, X-P & Gollnick P: Structure of the trp RNA-binding attenuation protein, TRAP, bound to RNA. (1999) Nature 401, 235-242.
- Antson AA: Single stranded RNA-binding proteins. (2000) Current Opinion in Structural Biology 10, 87-94.
- Hopcroft NH, Wendt AL, Gollnick P & Antson AA: Specificity of TRAP-RNA interactions: crystal structures of two complexes with different RNA sequences. Acta Cryst (2002) D58:615-621.
- Hopcroft NH, Wendt AL, Brzozowski A, Gollnick P, & Antson AA: TRAP-RNA interactions during transcription regulation: the role of spacers and trinucleotide repeats. J. Mol. Biol. (2004) 338:43-53.
- Shevtsov MB, Chen YL, Gollnick P & Antson AA: Anti-TRAP protein from Bacillus subtilis: crystallization and internal symmetry. Acta Cryst (2004) D60: 1311-1314.
- Gollnick P & Antson A: Going for RNA repeats. Nature Structural & Molecular Biology (2005) 12: 289 – 290.
- Gollnick P, Babitzke P, Antson A, Yanofsky C: Complexity in regulation of tryptophan biosynthesis in Bacillus subtilis. Ann. Rev. Genet. (2005) 39: 47-68.
- Shevtsov MB, Chen Y, Gollnick P and Antson AA: Crystal structure of Bacillus subtilis anti-TRAP protein, an antagonist of TRAP/RNA interaction. Proc. Natl. Acad. Sci. U. S. A., 2005, 102: 17600-17605.
- Shevtsov MB, Chen Y, Isupov MN, Leech A, Gollnick P, Antson AA. Bacillus licheniformis Anti-TRAP can assemble into two types of dodecameric particles with the same symmetry but inverted orientation of trimers. J Struct Biol., 2010, 170:127-133.
- Chen C-S, Smits C, Dodson GG, Shevtsov MB, Merlino N, Gollnick P and Antson AA: How to change the oligomeric state of a circular protein assembly: switch from 11-subunit to 12-subunit TRAP suggests a general mechanism. PLoS One 2011, 6: 1-11.
- Bayfield OW, Chen C-S, Patterson AR, Luan W, Smits C, Gollnick P, Antson AA: Trp RNA-binding attenuation protein: modifying symmetry and stability of a circular oligomer. PLoS ONE, 2012, e44309. doi:10.1371/journal.pone.0044309.