This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Biosynthesis → Cofactors, Prosthetic Groups, Electron Carriers Biosynthesis → Porphyrin Compounds Biosynthesis → Heme Biosynthesis|
Some taxa known to possess this pathway include : Anabaena variabilis, Aquifex aeolicus, Bacillus subtilis, Bradyrhizobium japonicum, Cupriavidus necator, Escherichia coli K-12 substr. MG1655, Halorhodospira halophila, Helicobacter pylori, Lactococcus lactis, Mycobacterium tuberculosis, Nitrosococcus oceani, Nitrosospira multiformis, Penicillium janthinellum, Pseudomonas aeruginosa, Salmonella enterica enterica serovar Typhi, Streptococcus sanguinis, Synechocystis sp. PCC 6803, Tetrahymena thermophila
Heme (protoheme, heme b) is an iron-containing prosthetic group found in many essential proteins including cytochromes and heme-containing globins. It is a porphyrin member of the cyclic tetrapyrroles. It is biosynthesized as protoheme, but different derivatives of protoheme can be formed that differ in modifications to the porphyrin ring, including how it is bound to the protein, such as heme o, heme a, heme c, and heme d.
The main difference between this protoheme biosynthetic pathway and the one shown at heme biosynthesis I (aerobic) is the presence of the enzyme coproporphyrinogen III dehydrogenase (EC 220.127.116.11), which catalyzes the transition from coproporphyrinogen III to protoporphyrinogen IX without the need for molecular oxygen. In addition, the enzyme protoporphyrinogen oxidase, which under aerobic conditions catalyzes the oxidation of protoporphyrinogen IX to protoporphyrin IX using molecular oxygen (EC 18.104.22.168), catalyzes this transition under anaerobic conditions using a quinone instead of molecular oxygen (EC 22.214.171.124).
Coproporphyrinogen III dehydrogenase (EC 126.96.36.199) is found in many bacteria, but does not appear to be present in archaea or eukarya (the only reference for its presence in a eukaryote is in the organism Tetrahymena thermophila, but this finding is based on sequence analysis alone, and has not been verified biochemically).
Important branch points within this pathway lead to biosynthesis of other important compounds such as vitamin B12 (cobalamin) (see adenosylcobalamin biosynthesis II (aerobic)), oxidized coenzyme F430 (see factor 430 biosynthesis), siroheme (see siroheme biosynthesis), heme D biosynthesis, and bacteriochlorophyll (see chlorophyllide a biosynthesis I (aerobic, light-dependent)).
Superpathways: superpathway of heme biosynthesis from uroporphyrinogen-III
Unification Links: EcoCyc:HEMESYN2-PWY
Caughey75: Caughey WS, Smythe GA, O'Keeffe DH, Maskasky JE, Smith MI (1975). "Heme A of cytochrome c oxicase. Structure and properties: comparisons with hemes B, C, and S and derivatives." J Biol Chem 250(19);7602-22. PMID: 170266
Troup95: Troup B, Hungerer C, Jahn D (1995). "Cloning and characterization of the Escherichia coli hemN gene encoding the oxygen-independent coproporphyrinogen III oxidase." J Bacteriol 1995;177(11);3326-31. PMID: 7768836
Boynton09: Boynton TO, Daugherty LE, Dailey TA, Dailey HA (2009). "Identification of Escherichia coli HemG as a novel, menadione-dependent flavodoxin with protoporphyrinogen oxidase activity." Biochemistry 48(29):6705-11. PMID: 19583219
Breckau03: Breckau D, Mahlitz E, Sauerwald A, Layer G, Jahn D (2003). "Oxygen-dependent coproporphyrinogen III oxidase (HemF) from Escherichia coli is stimulated by manganese." J Biol Chem 278(47);46625-31. PMID: 12975365
Cantoni84: Cantoni L, Dal Fiume D, Ruggieri R (1984). "Decarboxylation of uroporphyrinogen I and III in 2,3,7,8-tetrachlorodibenzo-p-dioxin induced porphyria in mice." Int J Biochem 16(5);561-5. PMID: 6724109
Dailey00: Dailey HA, Dailey TA, Wu CK, Medlock AE, Wang KF, Rose JP, Wang BC (2000). "Ferrochelatase at the millennium: structures, mechanisms and [2Fe-2S] clusters." Cell Mol Life Sci 57(13-14);1909-26. PMID: 11215517
Dailey94: Dailey HA, Sellers VM, Dailey TA (1994). "Mammalian ferrochelatase. Expression and characterization of normal and two human protoporphyric ferrochelatases." J Biol Chem 269(1);390-5. PMID: 8276824
DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114
Fujimoto12: Fujimoto N., Kosaka T., Yamada M. (2012). "Menaquinone as Well as Ubiquinone as a Crucial Component in the Escherichia coli Respiratory Chain." Chapter 10 in Chemical Biology, edited by D Ekinci, ISBN 978-953-51-0049-2.
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