Disease relevance of mntH

• Importance of conserved acidic residues in mntH, the Nramp homolog of Escherichia coli [1].

High impact information on mntH

• The genes are designated mntH because the two enterobacterial NRAMPs encode H+-stimulated, highly selective manganese(II) transport systems, accounting for all Mn2+ uptake in each species under the conditions tested [2].
• In S. typhimurium strain SL1344, mntH mutants showed no defect in invasion of or survival in cultured HeLa or RAW264.7 macrophage cells; however, expression of mntH:lacZ was induced severalfold by 3 h after invasion of the macrophages [2].
• In E. coli strains with chromosomal mntH-lacZ fusions, mntH was partially repressed by both Mn(2+) and Fe(2+) [3].
• Binding of purified MntR to the mntH operator was manganese dependent [3].
• The Fur binding site, localized within 22 nucleotides of the mntH operator by in vivo operator titration assays, resembles the Fur-box consensus sequence [3].

Chemical compound and disease context of mntH

• Dual repression by Fe(2+)-Fur and Mn(2+)-MntR of the mntH gene, encoding an NRAMP-like Mn(2+) transporter in Escherichia coli [3].
• SitABCD mediated increased transport of both iron and manganese as demonstrated by uptake of 55Fe, 59Fe or 54Mn in E. coli K-12 strains deficient for the transport of iron (aroB feoB) and manganese (mntH) respectively [4].
• Recombinant Escherichia coli JM109 (pZH3-5/pMT), harboring a manganese transport gene (mntA) and a metal-sequestering protein (metallothionein [MT]) gene, was cultivated to accumulate cadmium (Cd) in an aqueous phase [5].

Analytical, diagnostic and therapeutic context of mntH

• Site-directed mutagenesis was then carried out to change six conserved acidic residues (i.e., Asp-34, Glu-102, Asp-109, Glu-112, Glu-154, and Asp-238) in the E. coli Nramp homolog mntH [1].

References