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CATH Superfamily 3.30.70.250

Malonyl-CoA ACP transacylase, ACP-binding

The name of this superfamily has been modified since the most recent official CATH+ release (v4_2_0). At the point of the last release, this superfamily was named:

"
Malonyl-CoA ACP transacylase, ACP-binding
".

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 4133: Polyketide synthase type I

There are 4 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Beta-ketoacyl-[acyl-carrier-protein] synthase I. [EC: 2.3.1.41]
Acyl-[acyl-carrier-protein] + malonyl-[acyl-carrier-protein] = 3-oxoacyl- [acyl-carrier-protein] + CO(2) + [acyl-carrier-protein].
  • Responsible for the chain-elongation step of dissociated (type II) fatty-acid biosynthesis, i.e. the addition of two C atoms to the fatty-acid chain.
  • Escherichia coli mutants that lack this enzyme are deficient in unsaturated fatty acids.
  • Can use fatty acyl thioesters of ACP (C(2) to C(16)) as substrates, as well as fatty acyl thioesters of Co-A (C(4) to C(16)).
  • The substrate specificity is very similar to that of EC 2.3.1.179 with the exception that the latter enzyme is far more active with palmitoleoyl-ACP (C(16)-Delta(9)) as substrate, allowing the organism to regulate its fatty-acid composition with changes in temperature.
 74 A0A045J9J0 A0A083VQI4 A0A0D6J2K3 A0A0G4DUH6 A0A0H3LMX2 A0A0H3P6L9 A0A0J6VAN2 A0A0J6VGK3 A0A0J6VWH0 A0A0T9AYZ5
(64 more...)
Mycocerosate synthase. [EC: 2.3.1.111]
(1) A long-chain acyl-CoA + 3 methylmalonyl-CoA + 6 NADPH + a holo- [mycocerosate synthase] = a trimethylated-mycocerosoyl-[mycocerosate synthase] + 4 CoA + 3 CO(2) + 6 NADP(+) + 3 H(2)O. (2) A long-chain acyl-CoA + 4 methylmalonyl-CoA + 8 NADPH + a holo- [mycocerosate synthase] synthase = a tetramethylated-mycocerosoyl- [mycocerosate synthase] + 5 CoA + 4 CO(2) + 8 NADP(+) + 4 H(2)O.
  • This mycobacterial enzyme loads long-chain fatty acyl groups from their CoA esters and extends them by incorporation of three or four methylmalonyl (but not malonyl) residues, to form tri- or tetramethyl-branched fatty-acids, respectively, such as 2,4,6,8- tetramethyloctacosanoate (C(32)-mycocerosate).
  • Since the enzyme lacks a thioesterase domain, the products remain bound to the enzyme and require additional enzyme(s) for removal.
  • Even though the enzyme can accept C(6) to C(20) substrates in vitro, it prefers to act on C(14)-C(20) substrates in vivo.
 14 A0A0D6ISP9 A0A0H2ZTH7 A0A1K7C6R4 G4I4K1 U5WUV5 X7U4S6 X7V9N2 X7XUI3 X7XVQ4 X7Y5Z6
(4 more...)
6-deoxyerythronolide-B synthase. [EC: 2.3.1.94]
Propanoyl-CoA + 6 (2S)-methylmalonyl-CoA + 6 NADPH = 6-deoxyerythronolide B + 7 CoA + 6 CO(2) + H(2)O + 6 NADP(+).
  • The product, 6-deoxyerythronolide B, contains a 14-membered lactone ring and is an intermediate in the biosynthesis of erythromycin antibiotics.
  • Biosynthesis of 6-deoxyerythronolide B requires 28 active sites that are precisely arranged along three large polypeptides, denoted DEBS1, -2 and -3.
  • The polyketide product is synthesized by the processive action of a loading didomain, six extension modules and a terminal thioesterase domain.
  • Each extension module contains a minimum of a ketosynthase (KS), an acyltransferase (AT) and an acyl-carrier protein (ACP).
  • The KS domain both accepts the growing polyketide chain from the previous module and catalyzes the subsequent decarboxylative condensation between this substrate and an ACP-bound methylmalonyl extender unit, introduce by the AT domain.
  • This combined effort gives rise to a new polyketide intermediate that has been extended by two carbon atoms.
 4 A0A0D6J2K3 G4I0Q2 I7FMV0 Q0S9C4
[Acyl-carrier-protein] S-malonyltransferase. [EC: 2.3.1.39]
Malonyl-CoA + an [acyl-carrier-protein] = CoA + a malonyl-[acyl-carrier- protein].
  • Essential, along with EC 2.3.1.38, for the initiation of fatty-acid biosynthesis in bacteria.
  • Also provides the malonyl groups for polyketide biosynthesis.
  • The product of the reaction, malonyl-ACP, is an elongation substrate in fatty-acid biosynthesis.
  • In Mycobacterium tuberculosis, holo-ACP (the product of EC 2.7.8.7) is the preferred substrate.
  • This enzyme also forms part of the multienzyme complexes EC 4.1.1.88 and EC 4.1.1.89.
  • Malonylation of ACP is immediately followed by decarboxylation within the malonate-decarboxylase complex to yield acetyl-ACP, the catalytically active species of the decarboxylase.
  • In the enzyme from Klebsiella pneumoniae, methylmalonyl-CoA can also act as a substrate but acetyl-CoA cannot whereas the enzyme from Pseudomonas putida can use both as substrates.
  • The ACP subunit found in fatty-acid biosynthesis contains a pantetheine-4'-phosphate prosthetic group; that from malonate decarboxylase also contains pantetheine-4'-phosphate but in the form of a 2'-(5-triphosphoribosyl)-3'-dephospho-CoA prosthetic group.
 1 G4I0Q2