3FXR

Crystal structure of TsaR in complex with sulfate

Summary for 3FXR

• Entry DOI: 10.2210/pdb3fxr/pdb
• Related: 3FXQ 3FXU 3FZJ
• Descriptor: LysR type regulator of tsaMBCD, SULFATE ION, GLYCEROL, ... (5 entities in total)
• Functional Keywords: lysr-type, transcriptional regulator, lttr, tsar, whth, dna-binding, transcription, transcription regulation, transcription regulator
• Biological source: Comamonas testosteroni (Pseudomonas testosteroni)
• Total number of polymer chains: 2
• Total formula weight: 68700.49

Authors

Monferrer, D.,Tralau, T.,Kertesz, M.A.,Kikhney, A.,Svergun, D.,Uson, I. (deposition date: 2009-01-21, release date: 2010-01-26, Last modification date: 2023-11-01)

Primary citation

Monferrer, D.,Tralau, T.,Kertesz, M.A.,Dix, I.,Sola, M.,Uson, I.
Structural studies on the full-length LysR-type regulator TsaR from Comamonas testosteroni T-2 reveal a novel open conformation of the tetrameric LTTR fold
Mol.Microbiol., 75:1199-1214, 2010

PubMed Abstract: LysR-type transcriptional regulators (LTTRs) constitute the largest family of regulators in prokaryotes. The full-length structures of the LTTR TsaR from Comamonas testosteroni T-2 and its complex with the natural inducer para-toluensulfonate have been characterized by X-ray diffraction. Both ligand-free and complexed forms reveal a dramatically different quaternary structure from that of CbnR from Ralstonia eutropha, or a putative LysR-type regulator from Pseudomonas aeruginosa, the only other determined full-length structures of tetrameric LTTRs. Although all three show a head-to-head tetrameric ring, TsaR displays an open conformation, whereas CbnR and PA01-PR present additional contacts in opposing C-terminal domains that close the ring. Such large differences may be due to a broader structural versatility than previously assumed or either, reflect the intrinsic flexibility of tetrameric LTTRs. On the grounds of the sliding dimer hypothesis of LTTR activation, we propose a structural model in which the closed structures could reflect the conformation of a ligand-free LTTR, whereas inducer binding would bring about local changes to disrupt the interface linking the two compact C-terminal domains. This could lead to a TsaR-like, open structure, where the pairs of recognition helices are closer to each other by more than 10 A.

PubMed: 20059681
DOI: 10.1111/j.1365-2958.2010.07043.x

Experimental method

X-RAY DIFFRACTION (2.5 Å)