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CATH Superfamily 3.40.50.150

Vaccinia Virus protein VP39

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:

"
Vaccinia Virus protein VP39
".

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 135575: Type I polyketide synthase

There are 14 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
Lovastatin nonaketide synthase. [EC: 2.3.1.161]
9 malonyl-CoA + 11 NADPH + S-adenosyl-L-methionine + holo-[lovastatin nonaketide synthase] = dihydromonacolin L-[lovastatin nonaketide synthase] + 9 CoA + 9 CO(2) + 11 NADP(+) + S-adenosyl-L-homocysteine + 6 H(2)O.
  • This fungal enzyme system comprises a multi-functional polyketide synthase (PKS) and an enoyl reductase.
  • The PKS catalyzes many of the chain building reactions of EC 2.3.1.85, as well as a reductive methylation and a Diels-Alder reaction, while the reductase is responsible for three enoyl reductions that are necessary for dihydromonacolin L acid production.
 17 A0A084GE65 A0A0F4YEG7 A0A0F4YNJ2 A0A0F4Z407 B8MEL0 B8MJ47 B8MM59 B8MMZ2 B8MP12 B8MPC7
(7 more...)
[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.
 16 A0A0K0PDC2 A0A0K0PDC3 A0A0K0PDD1 A0A0K3A5Z5 A0Z9Q1 A0Z9Q2 A0ZEC0 A0ZEC2 A0ZEC3 T2IC67
(6 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.
 14 A0A073CFT1 A0A073CT05 A0A084GE65 B2J540 B8LUA8 B8LV30 B8LX33 B8MS66 B8MT30 G0Q180
(4 more...)
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.
 3 A0A1E7UVM7 S3IU67 S3IW94
NADPH:quinone reductase. [EC: 1.6.5.5]
NADPH + 2 quinone = NADP(+) + 2 semiquinone.
  • Specific for NADPH.
  • Catalyzes the one-electron reduction of certain quinones, with the orthoquinones 1,2-naphthoquinone and 9,10-phenanthrenequinone being the best substrates.
  • Dicoumarol (cf. EC 1.6.5.2) and nitrofurantoin are competitive inhibitors with respect to the quinone substrate.
  • The semiquinone free-radical product may be non-enzymically reduced to the hydroquinone or oxidized back to quinone in the presence of O(2).
  • Abundant in the lens of the eye of some mammalian species.
 3 G3J044 K9XLC2 K9XMT2
Phenylalanine racemase (ATP-hydrolyzing). [EC: 5.1.1.11]
ATP + L-phenylalanine + H(2)O = AMP + diphosphate + D-phenylalanine.
    		 2 A0A073CGA8 B8MPC7
    Enoyl-[acyl-carrier-protein] reductase (NADH). [EC: 1.3.1.9]
    An acyl-[acyl-carrier protein] + NAD(+) = a trans-2,3-dehydroacyl-[acyl- carrier protein] + NADH.
    • The enzyme catalyzes an essential step in fatty acid biosynthesis, the reduction of the 2,3-double bond in enoyl-acyl-[acyl-carrier- protein] derivatives of the elongating fatty acid moiety.
    • The enzyme from the bacterium Escherichia coli accepts substrates with carbon chain length from 4 to 18.
    • The enzyme from the bacterium Mycobacterium tuberculosis prefers substrates with carbon chain length from 12 to 24 carbons.
    		 2 A0A0F4Z361 A5AC09
    2-methylbutanoate polyketide synthase. [EC: 2.3.1.244]
    2 malonyl-CoA + [2-methylbutanoate polyketide synthase] + 2 NADPH + S-adenosyl-L-methionine = (S)-2-methylbutanoyl-[2-methylbutanoate polyketide synthase] + 2 CoA + 2 CO(2) + 2 NADP(+) + S-adenosyl-L- homocysteine + H(2)O.
    • This polyketide synthase enzyme forms the (S)-2-methylbutanoate side chain during lovastatin biosynthesis by the filamentous fungus Aspergillus terreus.
    • The overall reaction comprises a single condensation reaction followed by alpha-methylation, beta-ketoreduction, dehydration, and alpha,beta enoyl reduction.
    		 2 Q3S2U6 Q9Y7D5
    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.
    		 1 A0A084GE65
    Acetyl-CoA C-acetyltransferase. [EC: 2.3.1.9]
    2 acetyl-CoA = CoA + acetoacetyl-CoA.
      		 1 A0A0S2CHA9
      Aspartate racemase. [EC: 5.1.1.13]
      L-aspartate = D-aspartate.
      • Also acts, at half the rate, on L-alanine.
      		 1 G0Q180
      Phenylacetone monooxygenase. [EC: 1.14.13.92]
      Phenylacetone + NADPH + O(2) = benzyl acetate + NADP(+) + H(2)O.
      • NADH cannot replace NADPH as coenzyme.
      • In addition to phenylacetone, which is the best substrate found to date, this Baeyer-Villiger monooxygenase can oxidize other aromatic ketones (1-(4-hydroxyphenyl)propan-2-one, 1-(4-hydroxyphenyl)propan- 2-one and 3-phenylbutan-2-one), some alipatic ketones (e.g. dodecan- 2-one) and sulfides (e.g. 1-methyl-4-(methylsulfanyl)benzene).
      		 1 A0A084FZU5
      Acetolactate synthase. [EC: 2.2.1.6]
      2 pyruvate = 2-acetolactate + CO(2).
      • The reaction shown is in the pathway of biosynthesis of valine.
      • The enzyme can also transfer the acetaldehyde from pyruvate to 2-oxobutanoate, forming 2-ethyl-2-hydroxy-3-oxobutanoate, also known as 2-aceto-2-hydroxybutanoate, a reaction in the biosynthesis of isoleucine.
      • Formerly EC 4.1.3.18.
      		 1 A0A0A2V1Z9
      6-methylsalicylic acid synthase. [EC: 2.3.1.165]
      Acetyl-CoA + 3 malonyl-CoA + NADPH = 6-methylsalicylate + 4 CoA + 3 CO(2) + NADP(+).
      • A multienzyme complex with a 4'-phosphopantetheine prosthetic group on the acyl carrier protein.
      • It has a similar sequence to vertebrate type I fatty acid synthase.
      • Acetoacetyl-CoA can also act as a starter molecule.
      		 1 A0A084GE65
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