Cloned (Comment) | Organism |
---|---|
gene merA and mer operon, expression of MerA catalytic core and NmerA proteins in Escherichia coli strain XL-1 Blue | Serratia marcescens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | steady-state kinetic analysis, overview, apparent second-order rate constant for Hg(II) transfer from MerB to NmerA | Serratia marcescens |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
Hg + NADP+ + H+ | Serratia marcescens | organomercurials are converted to less toxic Hg(0) in the cytosol by the sequential action of organomercurial lyase MerB and mercuric ion reductase MerA, requiring transfer of Hg(II) from MerB to MerA, with transfer to the metallochaperone-like NmerA domain as the kinetically favored pathway in this coevolved system, overview | Hg2+ + NADPH | - |
? | |
additional information | Serratia marcescens | proposed model for reaction of NmerA with HgMerB and of GSH with HgMerB, overview | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Serratia marcescens | E0XF09 | plasmid-encoded mer operon | - |
Purification (Comment) | Organism |
---|---|
recombinant MerA catalytic core and NmerA proteins from Escherichia coli strain XL-1 Blue by anion exchange chromatography and gel filtreation, and separation by affinity chromatography | Serratia marcescens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
Hg + NADP+ + H+ | - |
Serratia marcescens | Hg2+ + NADPH | - |
? | |
Hg + NADP+ + H+ | organomercurials are converted to less toxic Hg(0) in the cytosol by the sequential action of organomercurial lyase MerB and mercuric ion reductase MerA, requiring transfer of Hg(II) from MerB to MerA, with transfer to the metallochaperone-like NmerA domain as the kinetically favored pathway in this coevolved system, overview | Serratia marcescens | Hg2+ + NADPH | - |
? | |
additional information | proposed model for reaction of NmerA with HgMerB and of GSH with HgMerB, overview | Serratia marcescens | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
MerA | - |
Serratia marcescens |
mercuric ion reductase | - |
Serratia marcescens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Serratia marcescens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.3 | - |
assay at | Serratia marcescens |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADPH | - |
Serratia marcescens |
General Information | Comment | Organism |
---|---|---|
evolution | organomercurials are converted to less toxic Hg(0) in the cytosol by the sequential action of organomercurial lyase MerB and mercuric ion reductase MerA, requiring transfer of Hg(II) from MerB to MerA, with transfer to the metallochaperone-like NmerA domain as the kinetically favored pathway in this coevolved system, overview. Hg(II) removal from MerB by the N-terminal domain, NmerA, and catalytic core C-terminal cysteine pairs of its coevolved MerA and by GSH, the major competing cellular thiol in gamma-proteobacteria. The reaction with a 10fold excess of NmerA over HgMerB removes about 92% of Hg(II), while similar extents of reaction require more than 1000fold excess of GSH | Serratia marcescens |
physiological function | organomercurials are converted to less toxic Hg(0) in the cytosol by the sequential action of organomercurial lyase MerB and mercuric ion reductase MerA, requiring transfer of Hg(II) from MerB to MerA, with transfer to the metallochaperone-like NmerA domain as the kinetically favored pathway in this coevolved system, overview. Hg(II) removal from MerB by the N-terminal domain, NmerA, and catalytic core C-terminal cysteine pairs of its coevolved MerA and by GSH, the major competing cellular thiol in gamma-proteobacteria. The reaction with a 10fold excess of NmerA over HgMerB removes about 92% of Hg(II), while similar extents of reaction require more than 1000fold excess of GSH. NmerA reacts more completely than GSH with HgMerB | Serratia marcescens |