In molecular biology, Beta-ketoacyl-ACP synthase EC 2.3.1.41, is an enzyme involved in fatty acid synthesis. It results in the formation of acetoacetyl ACP.
It is the enzyme that catalyses the condensation of malonyl-ACP with the growing fatty acid chain.[1] It is found as a component of a number of enzymatic systems, including fatty acid synthetase (FAS), which catalyses the formation of long-chain fatty acids from acetyl-CoA, malonyl-CoA and NADPH; the multi-functional 6-methysalicylic acid synthase (MSAS) from Penicillium patulum,[2] which is involved in the biosynthesis of a polyketide antibiotic; polyketide antibiotic synthase enzyme systems; Emericella nidulans multifunctional protein Wa, which is involved in the biosynthesis of conidial green pigment; Rhizobium nodulation protein nodE, which probably acts as a beta-ketoacyl synthase in the synthesis of the nodulation Nod factor fatty acyl chain; and yeast mitochondrial protein CEM1. The condensation reaction is a two step process, first the acyl component of an activated acyl primer is transferred to a cysteine residue of the enzyme and is then condensed with an activated malonyl donor with the concomitant release of carbon dioxide.
Beta-ketoacyl synthase contains two protein domains. The active site is located between the N- and C-terminal domains. The N-terminal domain contains most of the structures involved in dimer formation and also the active site cysteine. Residues from both domains contribute to substrate binding and catalysis[3]
See also
External links
References
- ↑ Kauppinen S, Siggaard-Andersen M, von Wettstein-Knowles P (1988). "beta-Ketoacyl-ACP synthase I of Escherichia coli: nucleotide sequence of the fabB gene and identification of the cerulenin binding residue". Carlsberg Res. Commun. 53 (6): 357–70. PMID 3076376.
- ↑ Beck J, Ripka S, Siegner A, Schiltz E, Schweizer E (September 1990). "The multifunctional 6-methylsalicylic acid synthase gene of Penicillium patulum. Its gene structure relative to that of other polyketide synthases". Eur. J. Biochem. 192 (2): 487–98. doi:10.1111/j.1432-1033.1990.tb19252.x. PMID 2209605.
- ↑ Huang W, Jia J, Edwards P, Dehesh K, Schneider G, Lindqvist Y (1998). "Crystal structure of beta-ketoacyl-acyl carrier protein synthase II from E.coli reveals the molecular architecture of condensing enzymes.". EMBO J 17 (5): 1183–91. doi:10.1093/emboj/17.5.1183. PMC 1170466. PMID 9482715.
This article incorporates text from the public domain Pfam and InterPro IPR014030
This article incorporates text from the public domain Pfam and InterPro IPR014031
|
---|
| 2.3.1: other than amino-acyl groups | |
---|
| 2.3.2: Aminoacyltransferases | |
---|
| 2.3.3: converted into alkyl on transfer | |
---|
|
- B
- enzm
- 1.1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 10
- 11
- 13
- 14
- 15-18
- 2.1
- 3.1
- 4.1
- 5.1
- 6.1-3
|
|
|
|
|
---|
| Synthesis |
| |
---|
| | |
---|
| Fatty acid desaturases | |
---|
| Triacyl glycerol | |
---|
|
---|
| Degradation |
Acyl transport | |
---|
| |
General | |
---|
| Unsaturated | |
---|
| Odd chain | |
---|
| Other | |
---|
|
---|
| | |
---|
| | |
---|
|
---|
|
|
mt, k, c/g/r/p/y/i, f/h/s/l/o/e, a/u, n, m
|
k, cgrp/y/i, f/h/s/l/o/e, au, n, m, epon
|
m (A16/C10), i (k, c/g/r/p/y/i, f/h/s/o/e, a/u, n, m)
|
|
|
|