1Z4H

The response regulator TorI belongs to a new family of atypical excisionase

Summary for 1Z4H

• Entry DOI: 10.2210/pdb1z4h/pdb
• NMR Information: BMRB: 6762
• Descriptor: Tor inhibition protein (1 entity in total)
• Functional Keywords: winged helix, reverse turn, protein binding, dna binding protein
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 7692.92

Authors

Elantak, L.,Ansaldi, M.,Guerlesquin, F.,Mejean, V.,Morelli, X. (deposition date: 2005-03-16, release date: 2005-08-09, Last modification date: 2024-05-22)

Primary citation

Elantak, L.,Ansaldi, M.,Guerlesquin, F.,Mejean, V.,Morelli, X.
Structural and genetic analyses reveal a key role in prophage excision for the TorI response regulator inhibitor
J.Biol.Chem., 280:36802-36808, 2005

PubMed Abstract: TorI (Tor inhibition protein) has been identified in Escherichia coli as a protein inhibitor acting through protein-protein interaction with the TorR response regulator. This interaction, which does not interfere with TorR DNA binding activity, probably prevents the recruitment of RNA polymerase to the torC promoter. In this study we have solved the solution structure of TorI, which adopts a prokaryotic winged-helix arrangement. Despite no primary sequence similarity, the three-dimensional structure of TorI is highly homologous to the (lambda)Xis, Mu bacteriophage repressor (MuR-DBD), and transposase (MuA-DBD) structures. We propose that the TorI protein is the structural missing link between the (lambda)Xis and MuR proteins. Moreover, in vivo assays demonstrated that TorI plays an essential role in prophage excision. Heteronuclear NMR experiments and site-directed mutagenesis studies have pinpointed out key residues involved in the DNA binding activity of TorI. Our findings suggest that TorI-related proteins identified in various pathogenic bacterial genomes define a new family of atypical excisionases.

PubMed: 16079126
DOI: 10.1074/jbc.M507409200

Experimental method

SOLUTION NMR