Category:PK
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				 (→Polyketide Synthase (PKS) in Actynomycetes)  | 
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| − | ==Polyketide Synthase (PKS)   | + | ==Polyketide Synthase (PKS) ==  | 
| + | |||
| + | {| class="wikitable"  | ||
| + | |-  | ||
| + | ! || actinomycetes (bacteria) || fungi  | ||
| + | |-  | ||
| + | ! non-aromatic  | ||
| + | | Type I<br/>(non-iterative) || Type II<br/>(iterative)  | ||
| + | |-  | ||
| + | ! aromatic  | ||
| + | | Type II<br/>(iterative)    || Type II<br/>(iterative)  | ||
| + | |}  | ||
===Type I PKS (non-iterative)===  | ===Type I PKS (non-iterative)===  | ||
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* products are aromatic (e.g. chiorotetracycline, pradimicin)  | * products are aromatic (e.g. chiorotetracycline, pradimicin)  | ||
| − | + | ||
| + | ==Non-ribosomal peptide synthase (NRPS)==  | ||
| + | |||
| + | |||
| + | vancomycin  | ||
==PKS in Fungi==  | ==PKS in Fungi==  | ||
Revision as of 09:19, 14 November 2009
Polyketide (ポリケチド)
Contents | 
Class Overview
Polyketides are synthesized through the polymerization of acetyl units (β-ketomethylene chain).
| 1st Class | ||
|---|---|---|
| PK4: Four C2 Units orsellinic acid, 6-methylsalicylic acid, triacetic acid lactone, asperlin, usnic acid, methylphloracetophenone, penicillic acid, patulin  | 
PK5: Five C2 Units citrinin, aflatoxin, augenone, sepedonin, stipitatonic acid  | 
PK6: Six C2 Units plumbagin, 7-methyljuglone, juglone, variotin  | 
| PK7: Seven and eight C2 Units Anthraquinone rings  | 
PK9: Nine C2 Units Tetracyclines  | |
Polyketide Synthase (PKS)
| actinomycetes (bacteria) | fungi | |
|---|---|---|
| non-aromatic |  Type I (non-iterative)  | 
 Type II (iterative)  | 
| aromatic |  Type II (iterative)  | 
 Type II (iterative)  | 
Type I PKS (non-iterative)
- multi catalytic domains exist in a single protein
 - chain length is determined by the number of catalytic domains
 - products are non-aromatic (e.g. erythromycin, nigericin)
 
Ref. Erythromycin biosynthesis in Nat Prod Rep 18, 380 (2001)
Type II PKS (iterative)
- three proteins (KSalpha, KSbeta, ACP) are repeatedly used for carbon chain elongation
 - chain length is determined by another protein, CLF
 - products are aromatic (e.g. chiorotetracycline, pradimicin)
 
Non-ribosomal peptide synthase (NRPS)
vancomycin
PKS in Fungi
- both aromatic and non-aromatic compounds are generated by iterative PKS
 - methyl branch is transferred from methionine, not methylmalonyl CoA
 
Ref. Dewick, PM Medicinal Natural Products (2009)