2HYG

The Structure of apo-MntR from Bacillus subtilis, Native Form

Summary for 2HYG

• Entry DOI: 10.2210/pdb2hyg/pdb
• Related: 2F5C 2F5D 2HYF
• Descriptor: Transcriptional regulator mntR (2 entities in total)
• Functional Keywords: transcriptional regulator, transcription
• Biological source: Bacillus subtilis
• Cellular location: Cytoplasm (Probable): P54512
• Total number of polymer chains: 1
• Total formula weight: 16787.13

Authors

Glasfeld, A.,Kliegman, J.I. (deposition date: 2006-08-06, release date: 2006-11-07, Last modification date: 2023-08-30)

Primary citation

DeWitt, M.A.,Kliegman, J.I.,Helmann, J.D.,Brennan, R.G.,Farrens, D.L.,Glasfeld, A.
The conformations of the manganese transport regulator of Bacillus subtilis in its metal-free state.
J.Mol.Biol., 365:1257-1265, 2007

PubMed Abstract: The manganese transport regulator (MntR) from Bacillus subtilis binds cognate DNA sequences in response to elevated manganese concentrations. MntR functions as a homodimer that binds two manganese ions per subunit. Metal binding takes place at the interface of the two domains that comprise each MntR subunit: an N-terminal DNA-binding domain and a C-terminal dimerization domain. In order to elucidate the link between metal binding and activation, a crystallographic study of MntR in its metal-free state has been undertaken. Here we describe the structures of the native protein and a selenomethionine-containing variant, solved to 2.8 A. The two structures contain five crystallographically unique subunits of MntR, providing diverse views of the metal-free protein. In apo-MntR, as in the manganese complex, the dimer is formed by dyad-related C-terminal domains that provide a conserved structural core. Similarly, each DNA-binding domain largely retains the folded conformation found in metal bound forms of MntR. However, compared to metal-activated MntR, the DNA-binding domains move substantially with respect to the dimer interface in apo-MntR. Overlays of multiple apo-MntR structures indicate that there is a greater range of positioning allowed between N and C-terminal domains in the metal-free state and that the DNA-binding domains of the dimer are farther apart than in the activated complex. To further investigate the conformation of the DNA-binding domain of apo-MntR, a site-directed spin labeling experiment was performed on a mutant of MntR containing cysteine at residue 6. Consistent with the crystallographic results, EPR spectra of the spin-labeled mutant indicate that tertiary structure is conserved in the presence or absence of bound metals, though slightly greater flexibility is present in inactive forms of MntR.

PubMed: 17118401
DOI: 10.1016/j.jmb.2006.10.080

Experimental method

X-RAY DIFFRACTION (2.8 Å)