1IXC

Crystal structure of CbnR, a LysR family transcriptional regulator

Summary for 1IXC

• Entry DOI: 10.2210/pdb1ixc/pdb
• Descriptor: LysR-type regulatory protein (2 entities in total)
• Functional Keywords: long alpha helix connecting dna binding and regulatory domains, dna binding protein
• Biological source: Cupriavidus necator
• Total number of polymer chains: 2
• Total formula weight: 64639.38

Authors

Muraoka, S.,Okumura, R.,Ogawa, N.,Miyashita, K.,Senda, T. (deposition date: 2002-06-18, release date: 2003-06-18, Last modification date: 2024-11-20)

Primary citation

Muraoka, S.,Okumura, R.,Ogawa, N.,Nonaka, T.,Miyashita, K.,Senda, T.
Crystal Structure of a Full-length LysR-type Transcriptional Regulator, CbnR: Unusual Combination of Two Subunit Forms and Molecular Bases for Causing and Changing DNA Bend
J.Mol.Biol., 328:555-566, 2003

PubMed Abstract: The LysR-type transcriptional regulator (LTTR) proteins are one of the most common transcriptional regulators in prokaryotes. Here we report the crystal structure of CbnR, which is one of the LTTRs derived from Ralstonia eutropha NH9. This is the first crystal structure of a full-length LTTR. CbnR was found to form a homo-tetramer, which seems to be a biologically active form. Surprisingly, the tetramer can be regarded as a dimer of dimers, whereby each dimer is composed of two subunits in different conformations. In the CbnR tetramer, the DNA-binding domains are located at the V-shaped bottom of the main body of the tetramer, and seem to be suitable to interact with a long stretch of the promoter DNA, which is approximately 60bp. Interaction between the four DNA-binding domains and the two binding sites on the target DNA is likely to bend the target DNA along the V-shaped bottom of the CbnR tetramer. The relaxation of the bent DNA, which occurs upon inducer binding to CbnR, seems to be associated with a quaternary structure change of the tetramer.

PubMed: 12706716
DOI: 10.1016/S0022-2836(03)00312-7

Experimental method

X-RAY DIFFRACTION (2.2 Å)