Protein: Probable cyclase otaY (EC 5.-.-.-) (Ochratoxin A biosynthesis cluster protein Y) (A0A1R3RGJ9)
Organism: Aspergillus carbonarius (strain ITEM 5010)
Function: Probable cyclase; part of the gene cluster that mediates the biosynthesis of ochratoxin A (OTA), a mycotoxin composed of a chlorinated type I polyketide dihydroisocoumarin moiety linked to L-phenylalanine, and demonstrated to have nephrotoxic, immunotoxic, genotoxic, neurotoxic, and teratogenic properties. OtaY is probably involved in the polyketide cyclization (Probable). The pathway begins with the highly reducing polyketide synthase otaA that catalyzes the formation of the isocoumarin group during the initial stages of biosynthesis, starting from one acetate and 4 malonate units, to originate the characteristic pentaketide skeleton 7-methylmellein (7-MM) of the OTA molecule. The newly identified cyclase otaY might be involved in the polyketide cyclization reaction during the initial steps of the OTA biosynthesis. 7-MM is then oxidized into 7-carboxymellein (also called ochratoxin beta) by the cytochrome P450 monooxygenase otaC. The NRPS encoded by the otaB gene is involved in the linking of phenylalanine to the dihydroisocoumarin ring. The reaction catalyzed by NRPS results in the production of ochratoxin B (OTB), which is the non-chlorinated analog of OTA and which subsequently serves as the substrate of the halogenase otaD for chlorination activity to form the final molecular structure of OTA, containing a chlorine atom in the C-5 position of the molecule (Probable).
Sequence: MTTPTPTTLKHHATTILTTLVNDRQTAAIEHLLHPTITLKHNDLPAMSKSELIAFWPEVLAQSPHFRVQIRDVIAEGNKVWVYSRVEGRLGEGVMDDFHMMVFDEEGLVVRSTGVQRVVEGEM
InterPro domains: - IPR032710: NTF2-like domain superfamily (homologous_superfamily) [8-115]
- IPR037401: SnoaL-like domain (domain) [20-112]
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0003824 (catalytic activity), GO:0016853 (isomerase activity), GO:0016872 (intramolecular lyase activity)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0009987 (cellular process), GO:0009058 (biosynthetic process), GO:0044237 (cellular metabolic process), GO:0044281 (small molecule metabolic process), GO:0071704 (organic substance metabolic process), GO:0044238 (primary metabolic process), GO:0042180 (cellular ketone metabolic process), GO:1901615 (organic hydroxy compound metabolic process), GO:1901360 (organic cyclic compound metabolic process), GO:1901576 (organic substance biosynthetic process), GO:0006629 (lipid metabolic process), GO:0044283 (small molecule biosynthetic process), GO:0046483 (heterocycle metabolic process), GO:0044255 (cellular lipid metabolic process), GO:0044249 (cellular biosynthetic process), GO:0006066 (alcohol metabolic process), GO:1901334 (lactone metabolic process), GO:1901362 (organic cyclic compound biosynthetic process), GO:0006720 (isoprenoid metabolic process), GO:1902644 (tertiary alcohol metabolic process), GO:0018130 (heterocycle biosynthetic process), GO:1901617 (organic hydroxy compound biosynthetic process), GO:0042181 (ketone biosynthetic process), GO:0008299 (isoprenoid biosynthetic process), GO:0046165 (alcohol biosynthetic process), GO:0008610 (lipid biosynthetic process), GO:1902645 (tertiary alcohol biosynthetic process), GO:1901336 (lactone biosynthetic process), GO:0006721 (terpenoid metabolic process), GO:0016114 (terpenoid biosynthetic process)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0005737 (cytoplasm), GO:0043229 (intracellular organelle), GO:0043227 (membrane-bounded organelle), GO:0009536 (plastid), GO:0043231 (intracellular membrane-bounded organelle)