Accepted name: pimeloyl-[acyl-carrier protein] synthase
Reaction: a long-chain acyl-[acyl-carrier protein] + 2 reduced flavodoxin + 3 O2 = pimeloyl-[acyl-carrier protein] + an n-alkanal + 2 oxidized flavodoxin + 3 H2O (overall reaction)
(1a) a long-chain acyl-[acyl-carrier protein] + reduced flavodoxin + O2 = a (7S)-7-hydroxy-long-chain-acyl-[acyl-carrier protein] + oxidized flavodoxin + H2O
(1b) a (7S)-7-hydroxy-long-chain-acyl-[acyl-carrier protein] + reduced flavodoxin + O2 = a (7R,8R)-7,8-dihydroxy-long-chain-acyl-[acyl-carrier protein] + oxidized flavodoxin + H2O
(1c) a (7R,8R)-7,8-dihydroxy-long-chain-acyl-[acyl-carrier protein] + reduced flavodoxin + O2 = a 7-oxoheptanoyl-[acyl-carrier protein] + an n-alkanal + oxidized flavodoxin + 2 H2O
(1d) a 7-oxoheptanoyl-[acyl-carrier protein] + oxidized flavodoxin + H2O = a pimeloyl-[acyl-carrier protein] + reduced flavodoxin + H+
Glossary: a long-chain acyl-[acyl-carrier protein] = an acyl-[acyl-carrier protein] thioester where the acyl chain contains 13 to 22 carbon atoms.
palmitoyl-[acyl-carrier protein] = hexadecanoyl-[acyl-carrier protein]
pimeloyl-[acyl-carrier protein] = 6-carboxyhexanoyl-[acyl-carrier protein]
Other name(s): bioI (gene name); P450BioI; CYP107H1
Systematic name: acyl-[acyl-carrier protein],reduced-flavodoxin:oxygen oxidoreductase (pimeloyl-[acyl-carrier protein]-forming)
Comments: A cytochrome P-450 (heme-thiolate) protein. The enzyme catalyses an oxidative C-C bond cleavage of long-chain acyl-[acyl-carrier protein]s of various lengths to generate pimeloyl-[acyl-carrier protein], an intermediate in the biosynthesis of biotin. The preferred substrate of the enzyme from the bacterium Bacillus subtilis is palmitoyl-[acyl-carrier protein] which then gives heptanal as the alkanal. The mechanism is similar to EC, cholesterol monooxygenase (side-chain-cleaving), followed by a hydroxylation step, which may occur spontaneously [2].
1.  Stok, J.E. and De Voss, J. Expression, purification, and characterization of BioI: a carbon-carbon bond cleaving cytochrome P450 involved in biotin biosynthesis in Bacillus subtilis. Arch. Biochem. Biophys. 384 (2000) 351–360. [PMID: 11368323]
2.  Cryle, M.J. and De Voss, J.J. Carbon-carbon bond cleavage by cytochrome p450(BioI)(CYP107H1). Chem. Commun. (Camb.) (2004) 86–87. [PMID: 14737344]
3.  Cryle, M.J. and Schlichting, I. Structural insights from a P450 Carrier Protein complex reveal how specificity is achieved in the P450(BioI) ACP complex. Proc. Natl. Acad. Sci. USA 105 (2008) 15696–15701. [PMID: 18838690]
4.  Cryle, M.J. Selectivity in a barren landscape: the P450(BioI)-ACP complex. Biochem. Soc. Trans. 38 (2010) 934–939. [PMID: 20658980]
[EC created 2013 as EC, transferred 2017 to EC]
Transferred entry: pimeloyl-[acyl-carrier protein] synthase. Now EC, pimeloyl-[acyl-carrier protein] synthase
[EC created 2013, deleted 2017]
Accepted name: 8-amino-7-oxononanoate synthase
Reaction: pimeloyl-[acyl-carrier protein] + L-alanine = 8-amino-7-oxononanoate + CO2 + holo-[acyl-carrier protein]
Glossary: pimeloyl-[acyl-carrier protein] = 6-carboxyhexanoyl-[acyl-carrier protein]
Other name(s): 7-keto-8-aminopelargonic acid synthetase; 7-keto-8-aminopelargonic synthetase; 8-amino-7-oxopelargonate synthase; bioF (gene name)
Systematic name: 6-carboxyhexanoyl-[acyl-carrier protein]:L-alanine C-carboxyhexanoyltransferase (decarboxylating)
Comments: A pyridoxal-phosphate protein. The enzyme catalyses the decarboxylative condensation of L-alanine and pimeloyl-[acyl-carrier protein], a key step in the pathway for biotin biosynthesis. Pimeloyl-CoA can be used with lower efficiency [5].
1.  Eisenberg, M.A. and Star, C. Synthesis of 7-oxo-8-aminopelargonic acid, a biotin vitamer, in cell-free extracts of Escherichia coli biotin auxotrophs. J. Bacteriol. 96 (1968) 1291–1297. [PMID: 4879561]
2.  Alexeev, D., Alexeeva, M., Baxter, R.L., Campopiano, D.J., Webster, S.P. and Sawyer, L. The crystal structure of 8-amino-7-oxononanoate synthase: a bacterial PLP-dependent, acyl-CoA-condensing enzyme. J. Mol. Biol. 284 (1998) 401–419. [PMID: 9813126]
3.  Ploux, O., Breyne, O., Carillon, S. and Marquet, A. Slow-binding and competitive inhibition of 8-amino-7-oxopelargonate synthase, a pyridoxal-5′-phosphate-dependent enzyme involved in biotin biosynthesis, by substrate and intermediate analogs. Kinetic and binding studies. Eur. J. Biochem. 259 (1999) 63–70. [PMID: 9914476]
4.  Webster, S.P. , Alexeev. D., Campopiano, D.J., Watt, R.M., Alexeeva, M., Sawyer, L. and Baxter, R. Mechanism of 8-amino-7-oxononanoate synthase: spectroscopic, kinetic, and crystallographic studies. Biochemistry 39 (2000) 516–528. [PMID: 10642176]
5.  Lin, S., Hanson, R.E. and Cronan, J.E. Biotin synthesis begins by hijacking the fatty acid synthetic pathway. Nat. Chem. Biol. 6 (2010) 682–688. [PMID: 20693992]
[EC created 1976, modified 2013]
Accepted name: pimelyl-[acyl-carrier protein] methyl ester esterase
Reaction: pimeloyl-[acyl-carrier protein] methyl ester + H2O = pimeloyl-[acyl-carrier protein] + methanol
Other name(s): BioH
Systematic name: pimeloyl-[acyl-carrier protein] methyl ester hydrolase
Comments: Involved in biotin biosynthesis in Gram-negative bacteria. The enzyme exhibits carboxylesterase activity, particularly toward substrates with short acyl chains [1,2]. Even though the enzyme can interact with coenzyme A thioesters [3], the in vivo role of the enzyme is to hydrolyse the methyl ester of pimeloyl-[acyl carrier protein], terminating the part of the biotin biosynthesis pathway that is catalysed by the fatty acid elongation enzymes [4].
1.  Sanishvili, R., Yakunin, A.F., Laskowski, R.A., Skarina, T., Evdokimova, E., Doherty-Kirby, A., Lajoie, G.A., Thornton, J.M., Arrowsmith, C.H., Savchenko, A., Joachimiak, A. and Edwards, A.M. Integrating structure, bioinformatics, and enzymology to discover function: BioH, a new carboxylesterase from Escherichia coli. J. Biol. Chem. 278 (2003) 26039–26045. [PMID: 12732651]
2.  Lemoine, Y., Wach, A. and Jeltsch, J.M. To be free or not: the fate of pimelate in Bacillus sphaericus and in Escherichia coli. Mol. Microbiol. 19 (1996) 645–647. [PMID: 8830257]
3.  Tomczyk, N.H., Nettleship, J.E., Baxter, R.L., Crichton, H.J., Webster, S.P. and Campopiano, D.J. Purification and characterisation of the BIOH protein from the biotin biosynthetic pathway. FEBS Lett. 513 (2002) 299–304. [PMID: 11904168]
4.  Lin, S., Hanson, R.E. and Cronan, J.E. Biotin synthesis begins by hijacking the fatty acid synthetic pathway. Nat. Chem. Biol. 6 (2010) 682–688. [PMID: 20693992]
[EC created 2011]