D9N1A1 · ACTS3_ALTAL
- ProteinHighly reducing polyketide synthase ACTTS3
- GeneACTTS3
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids2457 (go to sequence)
- Protein existenceEvidence at transcript level
- Annotation score4/5
Function
function
Highly reducing polyketide synthase; part of the gene clusters that mediate the biosynthesis of the host-selective toxins (HSTs) ACT-toxins responsible for brown spot of tangerine disease by the tangerine pathotype which affects tangerines and mandarins (PubMed:19271978).
ACT-toxins consist of three moieties, 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid (EDA), valine and a polyketide (PubMed:22846083).
ACT-toxin I is toxic to both citrus and pear; toxin II the 5''-deoxy derivative of ACT-toxin I, is highly toxic to pear and slightly toxic to citrus (PubMed:22846083).
On cellular level, ACT-toxins affect plasma membrane of susceptible cells and cause a sudden increase in loss of K+ after a few minutes of toxin treatment (PubMed:22846083).
The acyl-CoA ligase ACTT1, the hydrolase ACTT2, the enoyl-CoA hydratases ACTT3 and ACTT6, and the acyl-CoA synthetase ACTT5 are all involved in the biosynthesis of the AK-, AF- and ACT-toxin common 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid (EDA) structural moiety (PubMed:18944496, PubMed:18986255, PubMed:19271978).
The exact role of each enzyme, and of additional enzymes identified within the AF-toxin clusters have still to be determined (PubMed:18944496, PubMed:18986255, PubMed:19271978).
On the other hand, ACTTS1 to ACTTS4 are specific to the tangerine pathotype (PubMed:22846083).
The function of ACTTS3 is to elongate the polyketide chain portion of ACT-toxin that is unique to this toxin (PubMed:20192828).
The enoyl-reductase ACTTS2 might complement the missing enoyl-reductase (ER) domain in ACTTS3 in the synthesis of the polyketide portion of ACT-toxin (PubMed:20055645).
The roles of the nonribosomal peptide synthetases-related proteins ACTTS1 and ACTTS4 have also still not been elucidated (PubMed:22846083).
ACT-toxins consist of three moieties, 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid (EDA), valine and a polyketide (PubMed:22846083).
ACT-toxin I is toxic to both citrus and pear; toxin II the 5''-deoxy derivative of ACT-toxin I, is highly toxic to pear and slightly toxic to citrus (PubMed:22846083).
On cellular level, ACT-toxins affect plasma membrane of susceptible cells and cause a sudden increase in loss of K+ after a few minutes of toxin treatment (PubMed:22846083).
The acyl-CoA ligase ACTT1, the hydrolase ACTT2, the enoyl-CoA hydratases ACTT3 and ACTT6, and the acyl-CoA synthetase ACTT5 are all involved in the biosynthesis of the AK-, AF- and ACT-toxin common 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid (EDA) structural moiety (PubMed:18944496, PubMed:18986255, PubMed:19271978).
The exact role of each enzyme, and of additional enzymes identified within the AF-toxin clusters have still to be determined (PubMed:18944496, PubMed:18986255, PubMed:19271978).
On the other hand, ACTTS1 to ACTTS4 are specific to the tangerine pathotype (PubMed:22846083).
The function of ACTTS3 is to elongate the polyketide chain portion of ACT-toxin that is unique to this toxin (PubMed:20192828).
The enoyl-reductase ACTTS2 might complement the missing enoyl-reductase (ER) domain in ACTTS3 in the synthesis of the polyketide portion of ACT-toxin (PubMed:20055645).
The roles of the nonribosomal peptide synthetases-related proteins ACTTS1 and ACTTS4 have also still not been elucidated (PubMed:22846083).
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:18986255).
The CDCs are not essential for saprophytic growth but controls host-selective pathogenicity (PubMed:18986255).
Although conventional disruption could not be accomplished due to the high number of the copies identified in the genome, the high sequence identity among these copies is likely an advantage for RNA silencing, because it allows knockdown of all copies of this gene simultaneously (PubMed:18986255).
The CDCs are not essential for saprophytic growth but controls host-selective pathogenicity (PubMed:18986255).
Although conventional disruption could not be accomplished due to the high number of the copies identified in the genome, the high sequence identity among these copies is likely an advantage for RNA silencing, because it allows knockdown of all copies of this gene simultaneously (PubMed:18986255).
Cofactor
Note: Binds 1 phosphopantetheine covalently.
Pathway
Mycotoxin biosynthesis.
Features
Showing features for active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Active site | 179 | For beta-ketoacyl synthase activity | ||||
Sequence: C | ||||||
Active site | 316 | For beta-ketoacyl synthase activity | ||||
Sequence: H | ||||||
Active site | 356 | For beta-ketoacyl synthase activity | ||||
Sequence: H | ||||||
Active site | 641 | For malonyltransferase activity | ||||
Sequence: S | ||||||
Active site | 970 | Proton acceptor; for dehydratase activity | ||||
Sequence: H | ||||||
Active site | 1152 | Proton donor; for dehydratase activity | ||||
Sequence: D |
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | 3-oxoacyl-[acyl-carrier-protein] synthase activity | |
Molecular Function | methyltransferase activity | |
Molecular Function | oxidoreductase activity | |
Molecular Function | phosphopantetheine binding | |
Biological Process | fatty acid biosynthetic process | |
Biological Process | methylation | |
Biological Process | secondary metabolite biosynthetic process |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameHighly reducing polyketide synthase ACTTS3
- EC number
- Short namesHR-PKS ACTTS3
- 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 accessionD9N1A1
Organism-specific databases
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000444855 | 1-2457 | Highly reducing polyketide synthase ACTTS3 | |||
Sequence: MTPLREPIAVIGSACRFPGGANSPHKLWELLRDPRDILREFPDDRLVLSKFYNGNANHHGSTNVRNRSYLLSEDIRAFDAPFFHINPREADGMDPAQRILLEAVYEALEAAGYTMEQMQGTHTSVFVGVMNSDWWDLQMRDTETIATHAATGTARSIVSNRISYVFDLKGVSMTIDTACSSSLVALHQAVQSLRSGESTAAIVGGANILLDPAMYIAESTLQMLSPESRSRMWDKSANGYARGEGCAAVFLKPLTRAIADGDHIECVIRETGVSSDGRTQGITMPSAAAQAALIKSTYRSAGLDPLADRCQYFECHGTGTPAGDPIEAQAIAEAFFSHSGEDAEIYVGSIKTVIGHLEGCAGLAGLLKASLAIQNRTIPANMLFNDLNPLIGPYYRNLKILQAAKPWPQDIHGPRRASVNSFGFGGTNAHVILESYEPEMQGTHVLQERSFHGPLTFSACSKSSLLATISNFTSYIKTNPAVDLQNLAWVLQRKRTEFPVKQHFSGSTHARLIESMEAYLQNAGSSGLHNTTIDTKLLYPSEIPRVLGIFTGQGAQWATMGKEFIQNSYLFRESIDRSEAALVALPDPPSWSLISELFATVETSRLNEAELSQPLCTAIQIAIVDLMFAAGVKLDAVVGHSSGEIAAAYASGIISAADAMAIAYYRGFHAKRSHGTGGKRGGMVAAELSYEAALQFCEKVEWAGRLVLAASNSPSSITLSGDLDAVQEAHAYFEKENIFSRLLRVDTAYHSHHMIPCAEPYLTSLKACNIQVSQARSDCIWISSVSGDVQSSSEEQGALTGEYWVDNMVKPVLFSQAVQCSIWNSGPFESIVEIGPHFALKGPTTQVMEAVLESSPPYLSFMRRGHGIETFSDGLGRLWSKLGPSSVDLTGYWKACSSSHIKFQMLKGLPAYAWDHDKVYWKEGRISRNHRLRKDVPHELLGRRTADDSDYELRWRNVLRLTEIPWIRGHKFQGQVLFPAAGYVTMALEASKALVGDRHVRLFELRDICIRKALVLEEDQSSLETVFSVKRLNADFGIHDENMDLLEAEFSCYVCADETVGTLEKTVSGRIIIHLGSGVDVKLPPAAHFCTDLSPVDLDRFYSTVEELGLSYQGLFKGLDHAERMLNHSHALAVWENHSMGAGSMVHPALLDVMFQAIFVASISPAAPSTLWTPYLPVSIDRIIVDPDHIPVYSHPEVRAHIQAYVTKSSASSIVGDIHLLDSNGIHNGIQVEGLSLKSVAEPTEENDRSIFSQTVWDTDIASGTDFLRDRKEDAQESKLIHAIERVALFHFRSLVEAITVEKAKTLAWHHQLFLKAVKANIETIRTGGNPVVRQEWLCDTRETIEDLRAQHPGQIDLNLMHAVSEKLISIVCGETQILEVMLQDDMLNDFYMRGRGFETMNNCIARAVQQIAHKHPRAKYLEIGAGTGGTTHRILDTIESAYTSYEYTDISSAFFEKASHKFDKHASKMVFKVLDIEKDVVDQGFENGAYDVVIAANVLHATRTLSGTMGHIRSLLKPGGYLIFMEVTGDQLRLLFLFGALPGWWLGAGEGRSLGPGVSTIAWDNILRNTGFSGVDDVFYDFPDRSRHTCSVMISQAVDDQLRLLRDPLAATGMPISEQVLIIGGDTSSVSQLAYDTKRLISPWASCVAINNIDGLDSRRLPSRFSVICLTELDKPLFSEIMSEQRLSNLQNLFATANVVFWITSGCNEGTPVANMMVGIGRALATELPHLTLQFLDVKTVERLKPSIVAQSFFRLVLAKPLVMAEKSMLWTTEPELVFDGDDILIPRVLPDKEMNNRFNAARRPISENLWKESTCIELSNADNSSAPALFEIKNTIRPGETTIDVKYSVCLGKRCTFVLGVVSGTSDTVLAISDTNASSVRISKEHVFFLPHDFSGNSATLLLDTANHVLAAKLLRCISPNSIALIYEPGVRLAAAIRHHAHENTVDVFPATSNREKCGEGWAFIHPHATERDIRTIIPRNTGCFINLSFKPPGALSRALLQQTIIHGPDCLSQIVSSADGFLLEAAFNWATTGLLSLDSVETVSVQSYVGTTRPSRDFPLVFDWTAPRLPVTVKPLEPKGLFLPDKTYLMIGMTGDLGRSLCRWMAEHGARYVVLTSRNAEVDSAWIESMAAIGATVKVYKMDVSNRKSVLGVYTTIKNSLPTIAGVCNAAMVLEDRLFANMTVGALSKVFEPKVEGSKVLDEIFHELNLDFFILFSSLTSILGNGGQSNYHAANLFMTSMCAQRRARGLAASVMHIGMVADIGYVARSDRHIENHLRKLQYHPMSETDMHYLFAEAVMSSRADHPGNWNIVSGIETFVDAPGVKLRPPHYHNPRFAHYVREENARKEDLRTDKTEKSVKELLEDAISEEDVTTVFQQAFLIKLERLTQLESHRIDANKSLLNLGVDSLSAVEIRNWFLQTVGVDIPVLKLLRGDTVSEISIDATKKYLAQRTS | ||||||
Modified residue | 2411 | O-(pantetheine 4'-phosphoryl)serine | ||||
Sequence: S |
Keywords
- PTM
Expression
Induction
Expression is positively regulated by CSN5 during infection.
Structure
Family & Domains
Features
Showing features for domain, region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 5-435 | Ketosynthase family 3 (KS3) | ||||
Sequence: REPIAVIGSACRFPGGANSPHKLWELLRDPRDILREFPDDRLVLSKFYNGNANHHGSTNVRNRSYLLSEDIRAFDAPFFHINPREADGMDPAQRILLEAVYEALEAAGYTMEQMQGTHTSVFVGVMNSDWWDLQMRDTETIATHAATGTARSIVSNRISYVFDLKGVSMTIDTACSSSLVALHQAVQSLRSGESTAAIVGGANILLDPAMYIAESTLQMLSPESRSRMWDKSANGYARGEGCAAVFLKPLTRAIADGDHIECVIRETGVSSDGRTQGITMPSAAAQAALIKSTYRSAGLDPLADRCQYFECHGTGTPAGDPIEAQAIAEAFFSHSGEDAEIYVGSIKTVIGHLEGCAGLAGLLKASLAIQNRTIPANMLFNDLNPLIGPYYRNLKILQAAKPWPQDIHGPRRASVNSFGFGGTNAHVILES | ||||||
Region | 545-856 | Malonyl-CoA:ACP transacylase (MAT) domain | ||||
Sequence: RVLGIFTGQGAQWATMGKEFIQNSYLFRESIDRSEAALVALPDPPSWSLISELFATVETSRLNEAELSQPLCTAIQIAIVDLMFAAGVKLDAVVGHSSGEIAAAYASGIISAADAMAIAYYRGFHAKRSHGTGGKRGGMVAAELSYEAALQFCEKVEWAGRLVLAASNSPSSITLSGDLDAVQEAHAYFEKENIFSRLLRVDTAYHSHHMIPCAEPYLTSLKACNIQVSQARSDCIWISSVSGDVQSSSEEQGALTGEYWVDNMVKPVLFSQAVQCSIWNSGPFESIVEIGPHFALKGPTTQVMEAVLESSP | ||||||
Region | 938-1078 | N-terminal hotdog fold | ||||
Sequence: HELLGRRTADDSDYELRWRNVLRLTEIPWIRGHKFQGQVLFPAAGYVTMALEASKALVGDRHVRLFELRDICIRKALVLEEDQSSLETVFSVKRLNADFGIHDENMDLLEAEFSCYVCADETVGTLEKTVSGRIIIHLGSG | ||||||
Region | 938-1244 | Dehydratase (DH) domain | ||||
Sequence: HELLGRRTADDSDYELRWRNVLRLTEIPWIRGHKFQGQVLFPAAGYVTMALEASKALVGDRHVRLFELRDICIRKALVLEEDQSSLETVFSVKRLNADFGIHDENMDLLEAEFSCYVCADETVGTLEKTVSGRIIIHLGSGVDVKLPPAAHFCTDLSPVDLDRFYSTVEELGLSYQGLFKGLDHAERMLNHSHALAVWENHSMGAGSMVHPALLDVMFQAIFVASISPAAPSTLWTPYLPVSIDRIIVDPDHIPVYSHPEVRAHIQAYVTKSSASSIVGDIHLLDSNGIHNGIQVEGLSLKSVAEPT | ||||||
Domain | 938-1246 | PKS/mFAS DH | ||||
Sequence: HELLGRRTADDSDYELRWRNVLRLTEIPWIRGHKFQGQVLFPAAGYVTMALEASKALVGDRHVRLFELRDICIRKALVLEEDQSSLETVFSVKRLNADFGIHDENMDLLEAEFSCYVCADETVGTLEKTVSGRIIIHLGSGVDVKLPPAAHFCTDLSPVDLDRFYSTVEELGLSYQGLFKGLDHAERMLNHSHALAVWENHSMGAGSMVHPALLDVMFQAIFVASISPAAPSTLWTPYLPVSIDRIIVDPDHIPVYSHPEVRAHIQAYVTKSSASSIVGDIHLLDSNGIHNGIQVEGLSLKSVAEPTEE | ||||||
Region | 1091-1246 | C-terminal hotdog fold | ||||
Sequence: TDLSPVDLDRFYSTVEELGLSYQGLFKGLDHAERMLNHSHALAVWENHSMGAGSMVHPALLDVMFQAIFVASISPAAPSTLWTPYLPVSIDRIIVDPDHIPVYSHPEVRAHIQAYVTKSSASSIVGDIHLLDSNGIHNGIQVEGLSLKSVAEPTEE | ||||||
Region | 1399-1587 | Methyltransferase (CMet) domain | ||||
Sequence: ETMNNCIARAVQQIAHKHPRAKYLEIGAGTGGTTHRILDTIESAYTSYEYTDISSAFFEKASHKFDKHASKMVFKVLDIEKDVVDQGFENGAYDVVIAANVLHATRTLSGTMGHIRSLLKPGGYLIFMEVTGDQLRLLFLFGALPGWWLGAGEGRSLGPGVSTIAWDNILRNTGFSGVDDVFYDFPDRS | ||||||
Region | 2085-2281 | Ketoreductase (KR) domain | ||||
Sequence: FLPDKTYLMIGMTGDLGRSLCRWMAEHGARYVVLTSRNAEVDSAWIESMAAIGATVKVYKMDVSNRKSVLGVYTTIKNSLPTIAGVCNAAMVLEDRLFANMTVGALSKVFEPKVEGSKVLDEIFHELNLDFFILFSSLTSILGNGGQSNYHAANLFMTSMCAQRRARGLAASVMHIGMVADIGYVARSDRHIENHLR | ||||||
Domain | 2374-2451 | Carrier | ||||
Sequence: DVTTVFQQAFLIKLERLTQLESHRIDANKSLLNLGVDSLSAVEIRNWFLQTVGVDIPVLKLLRGDTVSEISIDATKKY |
Domain
Multidomain protein; including a ketosynthase (KS) that catalyzes repeated decarboxylative condensation to elongate the polyketide backbone; a malonyl-CoA:ACP transacylase (MAT) that selects and transfers the extender unit malonyl-CoA; a dehydratase (DH) domain that reduces hydroxyl groups to enoyl groups; a methyltransferase (CMeT) domain responsible for the incorporation of methyl groups; a ketoreductase (KR) domain that catalyzes beta-ketoreduction steps; and an acyl-carrier protein (ACP) that serves as the tether of the growing and completed polyketide via its phosphopantetheinyl arm.
Family and domain databases
Sequence
- Sequence statusComplete
- Length2,457
- Mass (Da)271,083
- Last updated2010-10-05 v1
- Checksum43CF5D9695EFE055