title: The genetic basis for bacterial mercury methylation.
abstract: Methylmercury is a potent neurotoxin produced in natural environments from inorganic mercury by anaerobic bacteria. However, until now the genes and proteins involved have remained unidentified. Here, we report a two-gene cluster, hgcA and hgcB, required for mercury methylation by Desulfovibrio desulfuricans ND132 and Geobacter sulfurreducens PCA. In either bacterium, deletion of hgcA, hgcB, or both genes abolishes mercury methylation. The genes encode a putative corrinoid protein, HgcA, and a 2[4Fe-4S] ferredoxin, HgcB, consistent with roles as a methyl carrier and an electron donor required for corrinoid cofactor reduction, respectively. Among bacteria and archaea with sequenced genomes, gene orthologs are present in confirmed methylators but absent in nonmethylators, suggesting a common mercury methylation pathway in all methylating bacteria and archaea sequenced to date.
authors: Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors: Jerry M
authors: JM
authors: Parks
authors: Alexander
authors: A
authors: Johs
authors: Mircea
authors: M
authors: Podar
authors: Romain
authors: R
authors: Bridou
authors: Richard A
authors: RA
authors: Hurt
authors: Steven D
authors: SD
authors: Smith
authors: Stephen J
authors: SJ
authors: Tomanicek
authors: Yun
authors: Y
authors: Qian
authors: Steven D
authors: SD
authors: Brown
authors: Craig C
authors: CC
authors: Brandt
authors: Anthony V
authors: AV
authors: Palumbo
authors: Jeremy C
authors: JC
authors: Smith
authors: Judy D
authors: JD
authors: Wall
authors: Dwayne A
authors: DA
authors: Elias
authors: Liyuan
authors: L
authors: Liang
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D045728:Corrinoids / Q000235:genetics; D045285:Desulfovibrio desulfuricans / Q000235:genetics* / Q000378:metabolism; D004785:Environmental Pollutants / Q000378:metabolism*; D005288:Ferredoxins / Q000235:genetics; D017353:Gene Deletion; D045302:Geobacter / Q000235:genetics* / Q000378:metabolism; D008628:Mercury / Q000378:metabolism*; D008745:Methylation; D008969:Molecular Sequence Data; D005810:Multigene Family
chemical_list: D001426:Bacterial Proteins; D045728:Corrinoids; D004785:Environmental Pollutants; D005288:Ferredoxins; D008628:Mercury