1on2
From Proteopedia
Bacillus subtilis Manganese Transport Regulator (MntR), D8M Mutant, Bound to Manganese
Overview
The Bacillus subtilis manganese transport regulator, MntR, binds Mn2+ as an effector and is a repressor of transporters that import manganese. A member of the diphtheria toxin repressor (DtxR) family of metalloregulatory proteins, MntR exhibits selectivity for Mn2+ over Fe2+. Replacement of a metal-binding residue, Asp8, with methionine (D8M) relaxes this specificity. We report here the X-ray crystal structures of wild-type MntR and the D8M mutant bound to manganese with 1.75 A and 1.61 A resolution, respectively. The 142-residue MntR homodimer has substantial structural similarity to the 226-residue DtxR but lacks the C-terminal SH3-like domain of DtxR. The metal-binding pockets of MntR and DtxR are substantially different. The cation-to-cation distance between the two manganese ions bound by MntR is 3.3 A, whereas that between the metal ions bound by DtxR is 9 A. D8M binds only a single Mn2+ per monomer, owing to alteration of the metal-binding site. The sole retained metal site adopts pseudo-hexacoordinate geometry rather than the pseudo-heptacoordinate geometry of the MntR metal sites.
About this Structure
1ON2 is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
Structure of the manganese-bound manganese transport regulator of Bacillus subtilis., Glasfeld A, Guedon E, Helmann JD, Brennan RG, Nat Struct Biol. 2003 Aug;10(8):652-7. PMID:12847518 Page seeded by OCA on Sat May 3 04:02:58 2008
