EC |
1.3.8.13 |
Accepted name: |
crotonobetainyl-CoA reductase |
Reaction: |
γ-butyrobetainyl-CoA + electron-transfer flavoprotein = crotonobetainyl-CoA + reduced electron-transfer flavoprotein |
Glossary: |
γ-butyrobetainyl-CoA = 4-(trimethylammonio)butanoyl-CoA
crotonobetainyl-CoA = (E)-4-(trimethylammonio)but-2-enoyl-CoA |
Other name(s): |
caiA (gene name) |
Systematic name: |
γ-butyrobetainyl-CoA:electron-transfer flavoprotein 2,3-oxidoreductase |
Comments: |
The enzyme has been purified from the bacterium Escherichia coli O44 K74, in which it forms a complex with EC 2.8.3.21, L-carnitine CoA-transferase. The electron donor is believed to be an electron-transfer flavoprotein (ETF) encoded by the fixA and fixB genes. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Roth, S., Jung, K., Jung, H., Hommel, R.K. and Kleber, H.P. Crotonobetaine reductase from Escherichia coli - a new inducible enzyme of anaerobic metabolization of L(–)-carnitine. Antonie Van Leeuwenhoek 65 (1994) 63–69. [PMID: 8060125] |
2. |
Preusser, A., Wagner, U., Elssner, T. and Kleber, H.P. Crotonobetaine reductase from Escherichia coli consists of two proteins. Biochim. Biophys. Acta 1431 (1999) 166–178. [DOI] [PMID: 10209289] |
3. |
Elssner, T., Hennig, L., Frauendorf, H., Haferburg, D. and Kleber, H.P. Isolation, identification, and synthesis of γ-butyrobetainyl-CoA and crotonobetainyl-CoA, compounds involved in carnitine metabolism of E. coli. Biochemistry 39 (2000) 10761–10769. [DOI] [PMID: 10978161] |
4. |
Walt, A. and Kahn, M.L. The fixA and fixB genes are necessary for anaerobic carnitine reduction in Escherichia coli. J. Bacteriol. 184 (2002) 4044–4047. [DOI] [PMID: 12081978] |
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[EC 1.3.8.13 created 2017] |
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EC |
2.8.3.21 |
Accepted name: |
L-carnitine CoA-transferase |
Reaction: |
(1) (E)-4-(trimethylammonio)but-2-enoyl-CoA + L-carnitine = (E)-4-(trimethylammonio)but-2-enoate + L-carnitinyl-CoA (2) 4-trimethylammoniobutanoyl-CoA + L-carnitine = 4-trimethylammoniobutanoate + L-carnitinyl-CoA |
Glossary: |
L-carnitine = (3R)-3-hydroxy-4-(trimethylammonio)butanoate
(E)-4-(trimethylammonio)but-2-enoate = crotonobetaine
4-trimethylammoniobutanoate = γ-butyrobetaine |
Other name(s): |
CaiB; crotonobetainyl/γ-butyrobetainyl-CoA:carnitine CoA-transferase |
Systematic name: |
(E)-4-(trimethylammonio)but-2-enoyl-CoA:L-carnitine CoA-transferase |
Comments: |
The enzyme is found in gammaproteobacteria such as Proteus sp. and Escherichia coli. It has similar activity with both substrates. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Engemann, C., Elssner, T. and Kleber, H.P. Biotransformation of crotonobetaine to L-(–)-carnitine in Proteus sp. Arch. Microbiol. 175 (2001) 353–359. [PMID: 11409545] |
2. |
Elssner, T., Engemann, C., Baumgart, K. and Kleber, H.P. Involvement of coenzyme A esters and two new enzymes, an enoyl-CoA hydratase and a CoA-transferase, in the hydration of crotonobetaine to L-carnitine by Escherichia coli. Biochemistry 40 (2001) 11140–11148. [DOI] [PMID: 11551212] |
3. |
Stenmark, P., Gurmu, D. and Nordlund, P. Crystal structure of CaiB, a type-III CoA transferase in carnitine metabolism. Biochemistry 43 (2004) 13996–14003. [DOI] [PMID: 15518548] |
4. |
Engemann, C., Elssner, T., Pfeifer, S., Krumbholz, C., Maier, T. and Kleber, H.P. Identification and functional characterisation of genes and corresponding enzymes involved in carnitine metabolism of Proteus sp. Arch. Microbiol. 183 (2005) 176–189. [DOI] [PMID: 15731894] |
5. |
Rangarajan, E.S., Li, Y., Iannuzzi, P., Cygler, M. and Matte, A. Crystal structure of Escherichia coli crotonobetainyl-CoA: carnitine CoA-transferase (CaiB) and its complexes with CoA and carnitinyl-CoA. Biochemistry 44 (2005) 5728–5738. [DOI] [PMID: 15823031] |
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[EC 2.8.3.21 created 2014] |
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EC |
4.2.1.149 |
Accepted name: |
crotonobetainyl-CoA hydratase |
Reaction: |
L-carnitinyl-CoA = (E)-4-(trimethylammonio)but-2-enoyl-CoA + H2O |
Glossary: |
L-carnitinyl-CoA = (3R)-3-hydroxy-4-(trimethylammonio)butanoyl-CoA
(E)-4-(trimethylammonio)but-2-enoyl-CoA = crotonobetainyl-CoA |
Other name(s): |
CaiD; L-carnityl-CoA dehydratase |
Systematic name: |
L-carnitinyl-CoA hydro-lyase [(E)-4-(trimethylammonio)but-2-enoyl-CoA-forming] |
Comments: |
The enzyme is also able to use crotonyl-CoA as substrate, with low efficiency [2]. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Engemann, C., Elssner, T. and Kleber, H.P. Biotransformation of crotonobetaine to L-(–)-carnitine in Proteus sp. Arch. Microbiol. 175 (2001) 353–359. [PMID: 11409545] |
2. |
Elssner, T., Engemann, C., Baumgart, K. and Kleber, H.P. Involvement of coenzyme A esters and two new enzymes, an enoyl-CoA hydratase and a CoA-transferase, in the hydration of crotonobetaine to L-carnitine by Escherichia coli. Biochemistry 40 (2001) 11140–11148. [DOI] [PMID: 11551212] |
3. |
Engemann, C., Elssner, T., Pfeifer, S., Krumbholz, C., Maier, T. and Kleber, H.P. Identification and functional characterisation of genes and corresponding enzymes involved in carnitine metabolism of Proteus sp. Arch. Microbiol. 183 (2005) 176–189. [DOI] [PMID: 15731894] |
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[EC 4.2.1.149 created 2014] |
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