| IED ID | IndEnz0010001059 |
| Enzyme Type ID | esterase001059 |
| Protein Name |
Carboxylesterase patB EC 3.1.1.1 Patulin biosynthesis cluster protein B |
| Gene Name | patB PEX2_082800 |
| Organism | Penicillium expansum (Blue mold rot fungus) |
| Taxonomic Lineage | cellular organisms Eukaryota Opisthokonta Fungi Dikarya Ascomycota saccharomyceta Pezizomycotina leotiomyceta Eurotiomycetes Eurotiomycetidae Eurotiales (green and blue molds) Aspergillaceae Penicillium Penicillium expansum (Blue mold rot fungus) |
| Enzyme Sequence | MQIINWASLLLVTWETVVAAELPIVDLGYQRHQAIGFNSTGRYYQFSNVRYAEPPLGPLRFSLPVSPRNRSHEVVNGKGLGNICPQSQACWFNVQGDFVSAVTAGSTFNFTAAYDQVYQQDECTKPRPVADQNPLESEDCLFLDVYVPEKVISKRRDGNGKSNPGAPVLVYFQDGAYVSGSKSDQNPSGLIATSREDGSTGIIYVGVNYRLGVFGWLSGQKFQSEGGLPNAGLYDERLALEWVQRHITKFGGDPSRVTVMGVSAGGGSITMQLTAYGRAIRPPFAQIIAQSPAWEPGTKTPAIEDDLLDSFLTLLNVSSLEEARRLPSQALLDANYELVASRPYGSGVFGPAIDGSFVPDSPKRLLLERKVDPSVRILTSYTANEGFMLAPANVTDDATFNRYVDVLLRGANASVRAHTSRVLYPPIFNGSWPYHSQHERANLLWSEVSTTCNTRYLHQAVATPGYAIEYAVKPAMHLSDTSSVFYNGQGSSSSLNATIAQLMQRQIVQFVKTGNPNVKGDPHVPLYHGQAHVLSLGDNGVRVEPALTNTDRCTYWQQVEF |
| Enzyme Length | 561 |
| Uniprot Accession Number | A0A075TXZ3 |
| Absorption | |
| Active Site | ACT_SITE 263; /note=Acyl-ester intermediate; /evidence=ECO:0000255|PROSITE-ProRule:PRU10039; ACT_SITE 385; /note=Charge relay system; /evidence=ECO:0000250|UniProtKB:P22303 |
| Activity Regulation | |
| Binding Site | BINDING 263; /note=Substrate; /evidence=ECO:0000250|UniProtKB:P22303 |
| Calcium Binding | |
| catalytic Activity | CATALYTIC ACTIVITY: Reaction=a carboxylic ester + H2O = a carboxylate + an alcohol + H(+); Xref=Rhea:RHEA:21164, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:29067, ChEBI:CHEBI:30879, ChEBI:CHEBI:33308; EC=3.1.1.1; Evidence={ECO:0000255|PROSITE-ProRule:PRU10039}; |
| DNA Binding | |
| EC Number | 3.1.1.1 |
| Enzyme Function | FUNCTION: Carboxylesterase; part of the gene cluster that mediates the biosynthesis of patulin, an acetate-derived tetraketide mycotoxin produced by several fungal species that shows antimicrobial properties against several bacteria (PubMed:30100914, PubMed:25625822, PubMed:30680886). The function of patB in patulin synthesis has still to be characterized (PubMed:30680886). The pathway begins with the synthesis of 6-methylsalicylic acid by the polyketide synthase (PKS) patK via condensation of acetate and malonate units. The 6-methylsalicylic acid decarboxylase patG then catalyzes the decarboxylation of 6-methylsalicylic acid to yield m-cresol (also known as 3-methylphenol). These first reactions occur in the cytosol. The intermediate m-cresol is then transported into the endoplasmic reticulum where the cytochrome P450 monooxygenase patH converts it to m-hydroxybenzyl alcohol, which is further converted to gentisyl alcohol by the cytochrome P450 monooxygenase patI. The oxidoreductases patJ and patO further convert gentisyl alcohol to isoepoxydon in the vacuole. PatN catalyzes then the transformation of isoepoxydon into phyllostine. The cluster protein patF is responsible for the conversion from phyllostine to neopatulin whereas the alcohol dehydrogenase patD converts neopatulin to E-ascladiol. The steps between isoepoxydon and E-ascladiol occur in the cytosol, and E-ascladiol is probably secreted to the extracellular space by one of the cluster-specific transporters patC or patM. Finally, the secreted patulin synthase patE catalyzes the conversion of E-ascladiol to patulin (PubMed:30680886) (Probable). {ECO:0000269|PubMed:25625822, ECO:0000269|PubMed:30100914, ECO:0000269|PubMed:30680886, ECO:0000305|PubMed:30680886}. |
| Temperature Dependency | |
| PH Dependency | |
| Pathway | PATHWAY: Mycotoxin biosynthesis; patulin biosynthesis. {ECO:0000269|PubMed:30680886}. |
| nucleotide Binding | |
| Features | Active site (2); Binding site (1); Chain (1); Glycosylation (8); Signal peptide (1) |
| Keywords | Cytoplasm;Glycoprotein;Hydrolase;Reference proteome;Signal |
| Interact With | |
| Induction | INDUCTION: Expression is correlated with the production of patulin (PubMed:25120234). Expression is positively regulated by the secondary metabolism regulator laeA (PubMed:27528575, PubMed:30100914). Expression is strongly decreased with increased sucrose concentrations. This decrease is lost in the presence of malic acid (PubMed:30100914). Expression is increased with pH changes from 2.5 to 3.5 in the presence of a limiting concentration of sucrose, 50 mM (PubMed:30100914). Natural phenols present in apple fruits such as chlorogenic acid or the flavonoid epicatechin modulate patulin biosynthesis. They increase expression in the absence of sucrose, have little impact in the presence of 15 mM sucrose, and decrease expression in 175 mM sucrose (PubMed:30100914). Expression is positively regulated by the patulin cluster-specific transcription factor patL (PubMed:25625822). Finally, expression is also positively regulated by the velvet family proteins transcription regulators veA, velB, velC, but not vosA (PubMed:30680886). {ECO:0000269|PubMed:25120234, ECO:0000269|PubMed:25625822, ECO:0000269|PubMed:27528575, ECO:0000269|PubMed:30100914, ECO:0000269|PubMed:30680886}. |
| Subcellular Location | SUBCELLULAR LOCATION: Cytoplasm, cytosol {ECO:0000269|PubMed:30680886}. |
| Modified Residue | |
| Post Translational Modification | |
| Signal Peptide | SIGNAL 1..19; /evidence=ECO:0000255 |
| Structure 3D | |
| Cross Reference PDB | - |
| Mapped Pubmed ID | - |
| Motif | |
| Gene Encoded By | |
| Mass | 61,487 |
| Kinetics | |
| Metal Binding | |
| Rhea ID | RHEA:21164 |
| Cross Reference Brenda |