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.
Synonyms: F430 biosynthesis
|Superclasses:||Biosynthesis → Cofactors, Prosthetic Groups, Electron Carriers Biosynthesis|
Some taxa known to possess this pathway include : Methanobacteria , Methanobacterium ivanovii , Methanococci , Methanomicrobia , Methanosarcina , Methanospirillum , Methanothermobacter thermautotrophicus , Methanothermus
Coenzyme F430 is a nickel containing tetrapyrrole cofactor, which is present in all methanogenic bacteria. It was initially observed in 1977 by Jean LeGall in extracts of Methanothermobacter thermautotrophicus. The name factor 430 (F430) was coined by Gunsalus and Wolfe who reported the absorbance maximumat 430 nm [Gunsalus78]. The compound belongs to the corphins, a class of compounds that combine structural elements of both corrins and porphyrins [Eschenmoser86].
In 1982 Ellefson et al showed that oxidized coenzyme F430 is a cofactor of the enzyme methyl-coenzyme M reductase (see methyl-coenzyme M reductase I and methyl-coenzyme M reductase II) [Ellefson82]. This enzyme catalyzes the final step of methane production in all methanogenic bacteria: the reduction of the methyl group in methyl-CoM to methane.
F430 exists in two distinct intracellular pools: either bound to methyl-CoM reductase or free of protein in the cytosol. Early literature on F430 was confusing due to reports of heterogeneity in F430 samples that depended on the isolation and purification procedures used in different laboratories. Later work showed that F430 exists primarily in two isomeric forms. These forms differ in the relative stereochemical disposition of acid side chains at positions 12 and 13 [Shiemke88].
The biosynthetic route leading to the formation of oxidized coenzyme F430 has not been elucidated completely. It has been shown that it is produced from uroporphyrinogen-III ( which in methanogens is synthesized from L-glutamate), through the intermediate precorrin-2 [Diekert80, Diekert80a, Jaenchen81, Thauer94]. A plausible scheme for the biosynthesis of oxidized coenzyme F430 from precorrin-2 has been proposed [Pfaltz87] and is illustrated here. However, all of these reactions are considered hypothetical at the moment.
Diekert80: Diekert G, Gilles HH, Jaenchen R, Thauer RK (1980). "Incorporation of 8 succinate per mol nickel into factors F430 by Methanobacterium thermoautotrophicum." Arch Microbiol 128(2);256-62. PMID: 7212929
Diekert80a: Diekert G, Jaenchen R, Thauer RK (1980). "Biosynthetic evidence for a nickel tetrapyrrole structure of factor F430 from Methanobacterium thermoautotrophicum." FEBS Lett 119(1);118-20. PMID: 7428919
Jaenchen81: Jaenchen, R., Diekert, G., Thauer, R. K. (1981). "Incorporation of methionine-derived methyl groups into factor F430 by Methanobacterium thermoautotrophicum." FEBS Letters 130 (1):133-136.
Pfaltz87: Pfaltz A, Kobelt A, Huster R, Thauer RK (1987). "Biosynthesis of coenzyme F430 in methanogenic bacteria. Identification of 15,17(3)-seco-F430-17(3)-acid as an intermediate." Eur J Biochem 170(1-2);459-67. PMID: 3691535
Shiemke88: Shiemke AK, Hamilton CL, Scott RA (1988). "Structural heterogeneity and purification of protein-free F430 from the cytoplasm of Methanobacterium thermoautotrophicum." J Biol Chem 263(12);5611-6. PMID: 3356701
Blanche89: Blanche F, Debussche L, Thibaut D, Crouzet J, Cameron B (1989). "Purification and characterization of S-adenosyl-L-methionine: uroporphyrinogen III methyltransferase from Pseudomonas denitrificans." J Bacteriol 171(8);4222-31. PMID: 2546914
Blanche91: Blanche F, Robin C, Couder M, Faucher D, Cauchois L, Cameron B, Crouzet J (1991). "Purification, characterization, and molecular cloning of S-adenosyl-L-methionine: uroporphyrinogen III methyltransferase from Methanobacterium ivanovii." J Bacteriol 173(15);4637-45. PMID: 1856165
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
Hansen97: Hansen J, Muldbjerg M, Cherest H, Surdin-Kerjan Y (1997). "Siroheme biosynthesis in Saccharomyces cerevisiae requires the products of both the MET1 and MET8 genes." FEBS Lett 401(1);20-4. PMID: 9003798
Woodcock96: Woodcock SC, Warren MJ (1996). "Evidence for a covalent intermediate in the S-adenosyl-L-methionine-dependent transmethylation reaction catalysed by sirohaem synthase." Biochem J 313 ( Pt 2);415-21. PMID: 8573073
Wu91b: Wu JY, Siegel LM, Kredich NM (1991). "High-level expression of Escherichia coli NADPH-sulfite reductase: requirement for a cloned cysG plasmid to overcome limiting siroheme cofactor." J Bacteriol 173(1);325-33. PMID: 1987123
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