ID   PKS3_ALOAR              Reviewed;         403 AA.
AC   C4MBZ5;
DT   29-MAY-2013, integrated into UniProtKB/Swiss-Prot.
DT   07-JUL-2009, sequence version 1.
DT   03-AUG-2022, entry version 35.
DE   RecName: Full=Aloesone synthase;
DE            EC=2.3.1.-;
DE   AltName: Full=Polyketide synthase 3;
GN   Name=PKS3;
OS   Aloe arborescens (Kidachi aloe).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; Liliopsida; Asparagales; Asphodelaceae;
OC   Asphodeloideae; Aloe.
OX   NCBI_TaxID=45385;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY,
RP   BIOPHYSICOCHEMICAL PROPERTIES, AND MUTAGENESIS OF ALA-207.
RX   PubMed=19348024; DOI=10.1111/j.1742-4658.2009.06971.x;
RA   Mizuuchi Y., Shi S.P., Wanibuchi K., Kojima A., Morita H., Noguchi H.,
RA   Abe I.;
RT   "Novel type III polyketide synthases from Aloe arborescens.";
RL   FEBS J. 276:2391-2401(2009).
CC   -!- FUNCTION: Catalyzes the iterative condensations of 6, 7 or 8 molecules
CC       of malonyl-CoA to produce various aromatic polyketides. Produces the
CC       heptaketide aloesone, the aglycone of aloesin, from 7 molecules of
CC       malonyl-CoA as a major product. Also able to produce a hexaketide
CC       pyrone, a heptaketide 6-(2-acetyl-3,5-dihydroxybenzyl)-4-hydroxy-2-
CC       pyrone, a novel heptaketide 6-(2-(2,4-dihydroxy-6-methylphenyl)-2-
CC       oxoethyl)-4-hydroxy-2-pyrone and octaketides SEK4/SEK4b.
CC       {ECO:0000269|PubMed:19348024}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=88 uM for malonyl-CoA {ECO:0000269|PubMed:19348024};
CC         Note=kcat is 0.0075 min(-1).;
CC       pH dependence:
CC         Optimum pH is 6.0. {ECO:0000269|PubMed:19348024};
CC   -!- PATHWAY: Secondary metabolite biosynthesis; flavonoid biosynthesis.
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
CC   -!- MISCELLANEOUS: A.arborescens is a medicinal plant rich in aromatic
CC       polyketides, such as pharmaceutically important aloenin (hexaketide),
CC       aloesin (heptaketide) and barbaloin (octaketide).
CC   -!- SIMILARITY: Belongs to the thiolase-like superfamily. Chalcone/stilbene
CC       synthases family. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; EF537574; ABS72373.1; -; mRNA.
DR   AlphaFoldDB; C4MBZ5; -.
DR   SMR; C4MBZ5; -.
DR   PRIDE; C4MBZ5; -.
DR   BioCyc; MetaCyc:MON-15005; -.
DR   UniPathway; UPA00154; -.
DR   GO; GO:0016747; F:acyltransferase activity, transferring groups other than amino-acyl groups; IDA:UniProtKB.
DR   GO; GO:0009813; P:flavonoid biosynthetic process; IDA:UniProtKB.
DR   Gene3D; 3.40.47.10; -; 2.
DR   InterPro; IPR012328; Chalcone/stilbene_synt_C.
DR   InterPro; IPR001099; Chalcone/stilbene_synt_N.
DR   InterPro; IPR011141; Polyketide_synthase_type-III.
DR   InterPro; IPR016039; Thiolase-like.
DR   PANTHER; PTHR11877; PTHR11877; 1.
DR   Pfam; PF02797; Chal_sti_synt_C; 1.
DR   Pfam; PF00195; Chal_sti_synt_N; 1.
DR   PIRSF; PIRSF000451; PKS_III; 1.
DR   SUPFAM; SSF53901; SSF53901; 2.
PE   1: Evidence at protein level;
KW   Acyltransferase; Flavonoid biosynthesis; Transferase.
FT   CHAIN           1..403
FT                   /note="Aloesone synthase"
FT                   /id="PRO_0000422576"
FT   ACT_SITE        174
FT                   /evidence="ECO:0000250"
FT   BINDING         281
FT                   /ligand="CoA"
FT                   /ligand_id="ChEBI:CHEBI:57287"
FT                   /evidence="ECO:0000250"
FT   BINDING         318..321
FT                   /ligand="CoA"
FT                   /ligand_id="ChEBI:CHEBI:57287"
FT                   /evidence="ECO:0000250"
FT   SITE            207
FT                   /note="Determines the polyketide chain length and product
FT                   specificity"
FT   MUTAGEN         207
FT                   /note="A->G: Turns into a octaketide synthase."
FT                   /evidence="ECO:0000269|PubMed:19348024"
FT   MUTAGEN         207
FT                   /note="A->M: Turns into a pentaketide synthase."
FT                   /evidence="ECO:0000269|PubMed:19348024"
SQ   SEQUENCE   403 AA;  44419 MW;  A16E6D3309E0568F CRC64;
     MGSLSDSTPL MKDVQGIRKA QKADGTATVM AIGTAHPPHI ISQDSYADFY FRVTNSEHKV
     ELKKKFDRIC KKTMIGKRYF NFDEEFLKKY PNITSFDKPS LNDRHDICIP GVPALGAEAA
     VKAIEEWGRP KSEITHLVFC TSGGVDMPSA DFQCAKLLGL RTNVNKYCIY MQGCYAGGTV
     MRYAKDLAEN NRGARVLMVC AELTIIALRG PNDSHIDNAI GNSLFGDGAA ALIVGSDPII
     GVEKPMFEIV CAKQTVIPNS EEVIHLHLRE SGLMFYMTKD SAATISNNIE ACLVDVFKSV
     GMTPPEDWNS LFWIPHPGGR AILDQVEAKL KLRPEKFSAT RTVLWDYGNM ISACVLYILD
     EMRRKSAAEG LETYGEGLEW GVLLGFGPGM TIETILLHSL PPV