Accepted name: (5R)-carbapenem-3-carboxylate synthase
Reaction: (3S,5S)-carbapenam-3-carboxylate + 2-oxoglutarate + O2 = (5R)-carbapen-2-em-3-carboxylate + succinate + CO2 + H2O
Glossary: (3S,5S)-carbapenam-3-carboxylate = (2S,5S)-7-oxo-1-azabicyclo[3.2.0]heptane-2-carboxylate
(5R)-carbapen-2-em-3-carboxylate = (5R)-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate
Other name(s): carC (gene name)
Systematic name: (3S,5S)-carbapenam-3-carboxylate,2-oxoglutarate:oxygen oxidoreductase (dehydrating)
Comments: Requires Fe2+. The enzyme is involved in the biosynthesis of the carbapenem β-lactam antibiotic (5R)-carbapen-2-em-3-carboxylate in the bacterium Pectobacterium carotovorum. It catalyses a stereoinversion at C-5 and introduces a double bond between C-2 and C-3.
1.  Clifton, I.J., Doan, L.X., Sleeman, M.C., Topf, M., Suzuki, H., Wilmouth, R.C. and Schofield, C.J. Crystal structure of carbapenem synthase (CarC). J. Biol. Chem. 278 (2003) 20843–20850. [PMID: 12611886]
2.  Stapon, A., Li, R. and Townsend, C.A. Carbapenem biosynthesis: confirmation of stereochemical assignments and the role of CarC in the ring stereoinversion process from L-proline. J. Am. Chem. Soc. 125 (2003) 8486–8493. [PMID: 12848554]
3.  Sleeman, M.C., Smith, P., Kellam, B., Chhabra, S.R., Bycroft, B.W. and Schofield, C.J. Biosynthesis of carbapenem antibiotics: new carbapenam substrates for carbapenem synthase (CarC). ChemBioChem 5 (2004) 879–882. [PMID: 15174175]
[EC created 2013]
Accepted name: carboxymethylproline synthase
Reaction: malonyl-CoA + (S)-1-pyrroline-5-carboxylate + H2O = CoA + (2S,5S)-5-carboxymethylproline + CO2
Other name(s): CarB (ambiguous)
Systematic name: malonyl-CoA:(S)-1-pyrroline-5-carboxylate malonyltransferase (cyclizing)
Comments: The enzyme is involved in the biosynthesis of the carbapenem β-lactam antibiotic (5R)-carbapen-2-em-3-carboxylate in the bacterium Pectobacterium carotovorum.
1.  Sleeman, M.C. and Schofield, C.J. Carboxymethylproline synthase (CarB), an unusual carbon-carbon bond-forming enzyme of the crotonase superfamily involved in carbapenem biosynthesis. J. Biol. Chem. 279 (2004) 6730–6736. [PMID: 14625287]
2.  Gerratana, B., Arnett, S.O., Stapon, A. and Townsend, C.A. Carboxymethylproline synthase from Pectobacterium carotorova: a multifaceted member of the crotonase superfamily. Biochemistry 43 (2004) 15936–15945. [PMID: 15595850]
3.  Sorensen, J.L., Sleeman, M.C. and Schofield, C.J. Synthesis of deuterium labelled L- and D-glutamate semialdehydes and their evaluation as substrates for carboxymethylproline synthase (CarB)—implications for carbapenem biosynthesis. Chem. Commun. (Camb.) (2005) 1155–1157. [PMID: 15726176]
4.  Sleeman, M.C., Sorensen, J.L., Batchelar, E.T., McDonough, M.A. and Schofield, C.J. Structural and mechanistic studies on carboxymethylproline synthase (CarB), a unique member of the crotonase superfamily catalyzing the first step in carbapenem biosynthesis. J. Biol. Chem. 280 (2005) 34956–34965. [PMID: 16096274]
5.  Batchelar, E.T., Hamed, R.B., Ducho, C., Claridge, T.D., Edelmann, M.J., Kessler, B. and Schofield, C.J. Thioester hydrolysis and C-C bond formation by carboxymethylproline synthase from the crotonase superfamily. Angew. Chem. Int. Ed. Engl. 47 (2008) 9322–9325. [PMID: 18972478]
6.  Hamed, R.B., Gomez-Castellanos, J.R., Thalhammer, A., Harding, D., Ducho, C., Claridge, T.D. and Schofield, C.J. Stereoselective C-C bond formation catalysed by engineered carboxymethylproline synthases. Nat. Chem. 3 (2011) 365–371. [PMID: 21505494]
[EC created 2013]
Transferred entry: carbapenam-3-carboxylate synthetase. The enzyme was discovered at the public-review stage to have been misclassified and so was withdrawn. See EC, carbapenam-3-carboxylate synthase
[EC created 2013, deleted 2013]
Accepted name: carbapenam-3-carboxylate synthase
Reaction: ATP + (2S,5S)-5-carboxymethylproline = AMP + diphosphate + (3S,5S)-carbapenam 3-carboxylate
Other name(s): CarA (ambiguous); CPS (ambiguous); carbapenam-3-carboxylate ligase; 6-methyl-(2S,5S)-5-carboxymethylproline cyclo-ligase (AMP-forming)
Systematic name: (2S,5S)-5-carboxymethylproline cyclo-ligase (AMP-forming)
Comments: The enzyme is involved in the biosynthesis of the carbapenem β-lactam antibiotic (5R)-carbapen-2-em-3-carboxylate in the bacterium Pectobacterium carotovorum.
1.  Gerratana, B., Stapon, A. and Townsend, C.A. Inhibition and alternate substrate studies on the mechanism of carbapenam synthetase from Erwinia carotovora. Biochemistry 42 (2003) 7836–7847. [PMID: 12820893]
2.  Miller, M.T., Gerratana, B., Stapon, A., Townsend, C.A. and Rosenzweig, A.C. Crystal structure of carbapenam synthetase (CarA). J. Biol. Chem. 278 (2003) 40996–41002. [PMID: 12890666]
3.  Raber, M.L., Arnett, S.O. and Townsend, C.A. A conserved tyrosyl-glutamyl catalytic dyad in evolutionarily linked enzymes: carbapenam synthetase and β-lactam synthetase. Biochemistry 48 (2009) 4959–4971. [PMID: 19371088]
4.  Arnett, S.O., Gerratana, B. and Townsend, C.A. Rate-limiting steps and role of active site Lys443 in the mechanism of carbapenam synthetase. Biochemistry 46 (2007) 9337–9345. [PMID: 17658887]
[EC created 2013 as, transferred 2013 to EC]

Data © 2001–2020 IUBMB
Web site © 2005–2020 Andrew McDonald