Cloned (Comment) | Organism |
---|---|
gene hemN, expression in Escherichia coli strain BL21(DE3) | Escherichia coli |
recombinant expression as GST-fusion protein | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
H2O2 | enzyme inactivation at 30% | Escherichia coli |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | HemN contains a catalytically essential [4Fe-4S] cluster that transfers an electron to bound S-adenosyl-L-methionine, thereby producing methionine and a 5'-deoxyadenosyl radical | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
coproporphyrinogen III + 2 S-adenosyl-L-methionine | Escherichia coli | - |
protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5'-deoxyadenosine | - |
? | |
coproporphyrinogen III + 2 S-adenosyl-L-methionine | Escherichia coli | via reaction intermediate harderoporphyrinogen, not isoharderoporphyrinogen | protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5'-deoxyadenosine | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Escherichia coli | - |
hemN | - |
Purification (Comment) | Organism |
---|---|
recombinant GST-tagged enzyme by glutathione affinity chromatography and ultrafiltration | Escherichia coli |
recombinant HemN from Escherichia coli strain BL21(DE3) | Escherichia coli |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
coproporphyrinogen III + 2 S-adenosyl-L-methionine = protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5'-deoxyadenosine | conversion of coproporphyrinogen III to protoporphyrinogen IX via the reaction intermediate harderoporphyrinogen. HemN contains a catalytically essential [4Fe-4S] cluster that transfers an electron to bound S-adenosyl-L-methionine, thereby producing methionine and a 5'-deoxyadenosyl radical. This radical then abstracts a hydrogen atom from the beta-carbon of the substrate propionate side chain, resulting in the formation of a coproporphyrinogenyl radical, overview | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
coproporphyrinogen III + 2 S-adenosyl-L-methionine | - |
Escherichia coli | protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5'-deoxyadenosine | - |
? | |
coproporphyrinogen III + 2 S-adenosyl-L-methionine | via reaction intermediate harderoporphyrinogen, not isoharderoporphyrinogen | Escherichia coli | protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5'-deoxyadenosine | - |
? | |
coproporphyrinogen III + 2 S-adenosyl-L-methionine | via reaction intermediate harderoporphyrinogen, not isoharderoporphyrinogen. During this reaction the propionate side chains on pyrrole rings A and B of coproporphyrinogen III are oxidatively decarboxylated to the corresponding vinyl groups of protoporphyrinogen IX. Two molecules of CO2 are released during the reaction and a final electron acceptor is required to take up two electrons from each side chain | Escherichia coli | protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5'-deoxyadenosine | - |
? | |
coproporphyrinogen III + 2 S-adenosyl-L-methionine | conversion of coproporphyrinogen III to protoporphyrinogen IX via the reaction intermediate harderoporphyrinogen | Escherichia coli | protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5'-deoxyadenosine | - |
? | |
harderoporphyrinogen + 2 S-adenosyl-L-methionine | HemN can utilize chemically synthesized harderoporphyrinogen as a substrate and converts it to protoporphyrinogen IX | Escherichia coli | protoporphyrinogen IX + 2 CO2 + 2 L-methionine + 2 5'-deoxyadenosine | - |
? | |
harderoporphyrinogen + S-adenosyl-L-methionine | chemical substrate sythesis, overview | Escherichia coli | protoporphyrinogen IX + CO2 + L-methionine + 5'-deoxyadenosine | - |
? |
Synonyms | Comment | Organism |
---|---|---|
HemN | - |
Escherichia coli |
oxygen-independent coproporphyrinogen III oxidase | - |
Escherichia coli |
oxygen-independent CPO | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Escherichia coli |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
S-adenosyl-L-methionine | - |
Escherichia coli | |
S-adenosyl-L-methionine | HemN contains a catalytically essential [4Fe-4S] cluster that transfers an electron to bound S-adenosyl-L-methionine, thereby producing methionine and a 5'-deoxyadenosyl radical | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
evolution | in eukaryotes and some bacteria, oxidative decarboxylation of coproporphyrinogen III is performed by the oxygen-dependent CPO HemF, EC 1.3.3.3. In most bacteria, the reaction is catalyzed by the oxygen-independent enzyme HemN. HemN belongs to the family of radical S-adenosyl-L-methionine enzymes. HemF and HemN are structurally completely unrelated and show different catalytic mechanisms, overview | Escherichia coli |