A7VMU5 · AMT4_ALTAL
- ProteinThioesterase AMT4
- GeneAMT4
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids261 (go to sequence)
- Protein existenceEvidence at transcript level
- Annotation score3/5
Function
function
Thioesterase; part of the gene clusters that mediate the biosynthesis of AM-toxins, host-selective toxins (HSTs) causing Alternaria blotch on apple, a worldwide distributed disease (PubMed:17990954).
AM-toxins are cyclic depsipeptides containing the 3 residues 2-hydroxy-isovaleric acid (2-HIV), dehydroalanine, L-alanine which are common for all 3 AM-toxins I to III. The fourth precursor is L-alpha-amino-methoxyphenyl-valeric acid (L-Amv) for AM-toxin I, L-alpha-amino-phenyl-valeric acid (L-Apv) for AM-toxin II, and L-alpha-amino-hydroxyphenyl-valeric acid (L-Ahv) for AM-toxin III (Probable). AM-toxins have two target sites for affecting susceptible apple cells; they cause invagination of the plasma membrane and electrolyte loss and chloroplast disorganization (PubMed:22846083).
The non-ribosomal peptide synthetase AMT1 contains 4 catalytic modules and is responsible for activation of each residue in AM-toxin (PubMed:10875335).
The aldo-keto reductase AMT2 catalyzes the conversion of 2-keto-isovaleric acid (2-KIV) to 2-hydroxy-isovaleric acid (2-HIV), one of the precursor residues incorporated by AMT1 during AM-toxin biosynthesis, by reduction of its ketone to an alcohol (PubMed:15066029).
The cytochrome P450 monooxygenase AMT3 and the thioesterase AMT4 are also important for AM-toxin production, but their exact function within the AM-toxin biosynthesis are not known yet (PubMed:17990954).
Up to 21 proteins (including AMT1 to AMT4) are predicted to be involved in AM-toxin biosynthesis since their expression ishighly up-regulated in AM-toxin-producing cultures (PubMed:17990954).
AM-toxins are cyclic depsipeptides containing the 3 residues 2-hydroxy-isovaleric acid (2-HIV), dehydroalanine, L-alanine which are common for all 3 AM-toxins I to III. The fourth precursor is L-alpha-amino-methoxyphenyl-valeric acid (L-Amv) for AM-toxin I, L-alpha-amino-phenyl-valeric acid (L-Apv) for AM-toxin II, and L-alpha-amino-hydroxyphenyl-valeric acid (L-Ahv) for AM-toxin III (Probable). AM-toxins have two target sites for affecting susceptible apple cells; they cause invagination of the plasma membrane and electrolyte loss and chloroplast disorganization (PubMed:22846083).
The non-ribosomal peptide synthetase AMT1 contains 4 catalytic modules and is responsible for activation of each residue in AM-toxin (PubMed:10875335).
The aldo-keto reductase AMT2 catalyzes the conversion of 2-keto-isovaleric acid (2-KIV) to 2-hydroxy-isovaleric acid (2-HIV), one of the precursor residues incorporated by AMT1 during AM-toxin biosynthesis, by reduction of its ketone to an alcohol (PubMed:15066029).
The cytochrome P450 monooxygenase AMT3 and the thioesterase AMT4 are also important for AM-toxin production, but their exact function within the AM-toxin biosynthesis are not known yet (PubMed:17990954).
Up to 21 proteins (including AMT1 to AMT4) are predicted to be involved in AM-toxin biosynthesis since their expression ishighly up-regulated in AM-toxin-producing cultures (PubMed:17990954).
Miscellaneous
Gene clusters encoding host-selective toxins (HSTs) are localized on conditionally dispensable chromosomes (CDCs), also called supernumerary chromosomes, where they are present in multiple copies (PubMed:17990954).
The CDCs are not essential for saprophytic growth but controls host-selective pathogenicity (PubMed:17990954).
The CDCs are not essential for saprophytic growth but controls host-selective pathogenicity (PubMed:17990954).
Pathway
Mycotoxin biosynthesis.
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | hydrolase activity | |
Biological Process | biosynthetic process |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameThioesterase AMT4
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Fungi > Dikarya > Ascomycota > Pezizomycotina > Dothideomycetes > Pleosporomycetidae > Pleosporales > Pleosporineae > Pleosporaceae > Alternaria > Alternaria sect. Alternaria > Alternaria alternata complex
Accessions
- Primary accessionA7VMU5
Phenotypes & Variants
Disruption phenotype
Produces smaller amounts of AM-toxin than the wild type but still causes lesions on apple leaves.
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000444845 | 1-261 | Thioesterase AMT4 | |||
Sequence: MSGLDDGLENPVLIQEYSRQGRATAAPAPLVLFHDGGGTLFSYFFLESLGRDVFGFADPRATSGQQWKDGITEMAIHYYKRMKMEIRPGSVILGGWSFGGLLALQLAQMIASDSAGGFEVVGVVLIDTSCPEKASYSSTVANGPIVPFRDDVPDCMQEIVRTSMVRNTEMLSQWEAPTWPQGYSKPPILLLRAAEGIDAKEERSLKLGWELCQHDVIDSVEMVPGNHYSLFESDNIGTLSSRLRESCKRMETPYRKAASSD |
Expression
Induction
Expression is up-regulated more than 10 fold in toxin producing cultures.
Structure
Sequence
- Sequence statusComplete
- Length261
- Mass (Da)28,752
- Last updated2007-10-23 v1
- ChecksumA2090383782B9FA2