Structural highlights
Function[MNTR_BACSU] Central regulator of manganese homeostasis. In the presence of manganese, it mediates repression of the manganese transporter MntH; under low manganese conditions, it activates the transcription of the mntABCD operon. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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