2ZP9

The Nature of the TRAP:Anti-TRAP complex

Summary for 2ZP9

• Entry DOI: 10.2210/pdb2zp9/pdb
• Related: 2ZCZ 2ZP8
• Descriptor: Transcription attenuation protein mtrB, Tryptophan RNA-binding attenuator protein-inhibitory protein, TRYPTOPHAN, ... (4 entities in total)
• Functional Keywords: protein-protein complex, transcription, rna-binding, transcription regulation, rna binding protein-transcription complex, rna binding protein/transcription
• Biological source: Bacillus stearothermophilus; More
• Cellular location: Cytoplasm (Probable): O31466
• Total number of polymer chains: 15
• Total formula weight: 104982.00

Authors

Watanabe, M.,Heddle, J.G.,Unzai, S.,Akashi, S.,Park, S.Y.,Tame, J.R.H. (deposition date: 2008-07-08, release date: 2009-02-03, Last modification date: 2023-11-01)

Primary citation

Watanabe, M.,Heddle, J.G.,Kikuchi, K.,Unzai, S.,Akashi, S.,Park, S.Y.,Tame, J.R.
The nature of the TRAP-Anti-TRAP complex.
Proc.Natl.Acad.Sci.USA, 106:2176-2181, 2009

PubMed Abstract: Tryptophan biosynthesis is subject to exquisite control in species of Bacillus and has become one of the best-studied model systems in gene regulation. The protein TRAP (trp RNA-binding attenuation protein) predominantly forms a ring-shaped 11-mer, which binds cognate RNA in the presence of tryptophan to suppress expression of the trp operon. TRAP is itself regulated by the protein Anti-TRAP, which binds to TRAP and prevents RNA binding. To date, the nature of this interaction has proved elusive. Here, we describe mass spectrometry and analytical centrifugation studies of the complex, and 2 crystal structures of the TRAP-Anti-TRAP complex. These crystal structures, both refined to 3.2-A resolution, show that Anti-TRAP binds to TRAP as a trimer, sterically blocking RNA binding. Mass spectrometry shows that 11-mer TRAP may bind up to 5 AT trimers, and an artificial 12-mer TRAP may bind 6. Both forms of TRAP make the same interactions with Anti-TRAP. Crystallization of wild-type TRAP with Anti-TRAP selectively pulls the 12-mer TRAP form out of solution, so the crystal structure of wild-type TRAP-Anti-TRAP complex reflects a minor species from a mixed population.

PubMed: 19164760
DOI: 10.1073/pnas.0801032106

Experimental method

X-RAY DIFFRACTION (3.2 Å)