Protein: Type III polyketide synthase A (PKS-A) (EC 2.3.1.-) (Hydroxyalkyl alpha-pyrone synthase PKS-A) (Protein LESS ADHESIVE POLLEN 6) (O23674)
Organism: Arabidopsis thaliana (Mouse-ear cress)
Function: Plant type III polyketide synthases (PKSs) that catalyzes the condensation of malonyl-CoA units with various CoA ester starter molecules to generate a diverse array of natural products including long-chain alkyl alpha-pyrones. Accepts up to C(20) chain-length fatty acyl CoAs as starter substrates, and carries out sequential condensations with malonyl-CoA to produce triketide and tetraketide alpha-pyrones, potential sporopollenin precursors. Favorite substrates for are midchain- and v-hydroxylated fatty acyl-CoAs (e.g. 12-hydroxyoctadecanoyl-CoA and 16-hydroxyhexadecanoyl-CoA). Required for pollen development and sporopollenin biosynthesis, the major constituent of exine in the outer pollen wall. In vitro, can use 4-coumaroyl-coenzyme A as substrate to produce bis-noryangonin and fatty acyl-coenzyme A as substrate to produce medium-chain alkyl pyrones. May play a role in both the synthesis of pollen fatty acids and phenolics found in exine.
Subcellular location: Endoplasmic reticulum {ECO:0000269|PubMed:21193570, ECO:0000269|PubMed:23632852}.
Sequence: MSNSRMNGVEKLSSKSTRRVANAGKATLLALGKAFPSQVVPQENLVEGFLRDTKCDDAFIKEKLEHLCKTTTVKTRYTVLTREILAKYPELTTEGSPTIKQRLEIANEAVVEMALEASLGCIKEWGRPVEDITHIVYVSSSEIRLPGGDLYLSAKLGLRNDVNRVMLYFLGCYGGVTGLRVAKDIAENNPGSRVLLTTSETTILGFRPPNKARPYDLVGAALFGDGAAAVIIGADPRECEAPFMELHYAVQQFLPGTQNVIEGRLTEEGINFKLGRDLPQKIEENIEEFCKKLMGKAGDESMEFNDMFWAVHPGGPAILNRLETKLKLEKEKLESSRRALVDYGNVSSNTILYVMEYMRDELKKKGDAAQEWGLGLAFGPGITFEGLLIRSLTSS
InterPro domains: - IPR001099: Chalcone/stilbene synthase, N-terminal (domain) [14-236]
- IPR016039: Thiolase-like (homologous_superfamily) [2-394]
- IPR012328: Chalcone/stilbene synthase, C-terminal (domain) [245-392]
- IPR011141: Polyketide synthase, type III (family) [12-394]
Interaction partners: - Putative acyl-activating enzyme 19
- Tetraketide alpha-pyrone reductase 1
- Cytochrome P450 704B1
- 4-coumarate--CoA ligase-like 1
- Cytochrome P450 703A2
- Tetraketide alpha-pyrone reductase 2
- holo-[acyl-carrier-protein] synthase
- holo-[acyl-carrier-protein] synthase
- ABC transporter G family member 26
- Short-chain dehydrogenase reductase ATA1
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005488 (binding), GO:0003824 (catalytic activity), GO:0016740 (transferase activity), GO:0005515 (protein binding), GO:0016746 (acyltransferase activity), GO:0016747 (acyltransferase activity, transferring groups other than amino-acyl groups)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0032502 (developmental process), GO:0009987 (cellular process), GO:0032501 (multicellular organismal process), GO:0048869 (cellular developmental process), GO:0048856 (anatomical structure development), GO:0007275 (multicellular organism development), GO:0009058 (biosynthetic process), GO:0009653 (anatomical structure morphogenesis), GO:0044237 (cellular metabolic process), GO:0071840 (cellular component organization or biogenesis), GO:0019748 (secondary metabolic process), GO:0071704 (organic substance metabolic process), GO:0048646 (anatomical structure formation involved in morphogenesis), GO:0032989 (cellular component morphogenesis), GO:0044550 (secondary metabolite biosynthetic process), GO:0044085 (cellular component biogenesis), GO:1901576 (organic substance biosynthetic process), GO:0044249 (cellular biosynthetic process), GO:0016043 (cellular component organization), GO:0006725 (cellular aromatic compound metabolic process), GO:0048229 (gametophyte development), GO:0010927 (cellular component assembly involved in morphogenesis), GO:0030638 (polyketide metabolic process), GO:0009555 (pollen development), GO:0010208 (pollen wall assembly), GO:0019438 (aromatic compound biosynthetic process), GO:0045229 (external encapsulating structure organization), GO:0030639 (polyketide biosynthetic process), GO:0022607 (cellular component assembly), GO:0010584 (pollen exine formation)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0005737 (cytoplasm), GO:0012505 (endomembrane system), GO:0043229 (intracellular organelle), GO:0005783 (endoplasmic reticulum), GO:0043227 (membrane-bounded organelle), GO:0043231 (intracellular membrane-bounded organelle)