Function
Non-reducing polyketide synthase; part of the gene cluster that mediates the biosynthesis of nigerpyrone and its derivatives carbonarone A and pestalamide A (PubMed:30384904). The biosynthesis pathway begins with the polyketide assembly by epaA to form phenylacetyl triketide precursor from successive condensation of two malonyl-CoA, presumably with one phenylacetyl-CoA starter unit produced by the phenylacetyl-CoA ligase epaB (PubMed:30384904). For the nigerpyrone biosynthesis, the reactive polyketide chain is released as an aldehyde through the R-domain. A nonenzymatic cyclization and dehydration may create nigerpyrone (PubMed:30384904). For the biosynthesis of carbonarone A and pestalamide A, an extra methyl group is added through the C-methyltransferase domain. Several further steps involving the dehydrogenase orf1, the cytochrome P450 monooxygenase orf2 and the FAD-dependent monooxygenase orf3 are required to form a carbonarone A precursor which is converted to carbonarone A via cyclization (PubMed:30384904). The O-acetyltransferase epaC could catalyze the transfer of 2-methylsuccinyl-CoA, a common intermediate in the ethylmalonyl-CoA pathway, to generate the final product pestalamide A (Probable).
Sequence
MVTTTRATNPTNTLLLFGPQALSFSTATFADIHARVVQTSENAWIKQTITSLPGLWDALVKEFPQYGALEGKQLLRDLDRWFETGTMEHAEPHLPNILLSPMVVITQLTEYVDYLKTMPHAADQQTETVGFCTGLLTALAASLASDIKGIRQYGAIAIKLAMIIGAVVDVQDITSPNGPSKSLAVAWDSAETQDRLNQIIDQSPEVYISVEYDYNRATITTAARSISSLQQRLRNAGLIASEIGLRGRFHCACYKNDIEALSKFCDSVPSLCLPDAAVLVLPTRSNDAGSFILSGKLHHCALRSILLDTSHWYQTLEVIRQSCLKSPSSMVVSFGPERCIPPSILKGLSSIVTTAAEYQPSYLHRDPELCNPNEIAVIGMSCKVAGADDVDEFWDLLCKAESQHQEVPKERFGFESAFREVDPTRKWYGNFINEHDCFDHKFFKKSAREIAATDPQQRQMLQVAYQAVEQSGYFTTPKSDKDRKIGCYIGVCAADYEYNVACHPPNAFMATGNLKSFVAGKISHWFGWTGPGLCIDTACSSSLVAVHQACQAILTGDCTAALAGGANIITHPLWYQNLAAASFLSPTGQCKPFDASADGYCRGEGFAAVFLKKMSAAIADGDMIIGSIKATAVNQNQNCTPVFVPNAPTLSDLFRDVLDRSQLTANQITVVEAHGTGTQVGDPAEYQSIRNVLGGPSRSTPLLFGSVKGLVGHTECTSGAVSLVKTLLMQQHEAIPPQPSFDRLNPEIPVSESDNMQIATRFSPWTAEYRAALINNYGACGSNASMVVAQAPRTEQRRSATRRTSVVLDYPFRLCGSDDRALRAYSERLLRFIASGIKDGISVADLAFNVCRQSNPTLDRSLAFACRTTQEVEEKLRAFVAGNQGLIATSRSKTPREVILCFGGQISNYVGLDREVYDNVALLRKHLAICDAACRDLGVDSIFPGIFQKSPISDPVKLQTILFSTQYSSAKAWMDSGVRPVAAVGHSFGELTALCATGILSLADAMKMIVGRATVIRDFWGEDKGSMIAVEADENRVQRLLAEAAKQCELIHARAPTIACVNGPTSYTLAGPVKSIDIVTEVISKLSDSGPSIRSKRLKVTNAFHSTLVEPLMEELEKVGQHLTFNTPTMQLERAIKHYSDATLTSDYVYDHMRNPVYFNQAVQRLAQQYPDSVWLEAGSNSTITSMASRALGSPRSLHFQAVNITSDDSWSMLITSTLSLWKQGISTNFWAYHAEQTYEYNPVLLPPYQFEPSRHWMELKVPSSMNNGKVQCGARDEEGPPKTLWSLIEASDKVARFQINTAAPKYVELVSGHVIANTAPICPATVEVDIVVEALRSLRPDFMDSNLQPQVLAVTNQSPICIDPNRSVWLECQAMDSNSVWEWRIVSDSLQEPGTSSSAHVLGKLAFLSGQDEVKQQESEFMRLERLIGHQRCVDLLNTTEADDIIQGRNIYTTFAGVVDYGEQYRGLKKIVGKGLESAGRVQKKPSEESWLDAHLGDCFSQVGGIWVNCMTDHNPDDMFIATGFEKWVRSPALRHGQPRSEIWDVLACHHRSSEQTYLTDIFIFDAEQGALTEVILGINYHKVAKASMSKILSRLSGTEAAPSSSTRAHPTSSSSPRLPGPSVPEDKSQNETQPAGTNAVAKKKSEKSAQQNVLEKTRALLAEISGLEPSEIEAETGLADIGIDSLMGMELARDLEALFKCPLLGDELANVTTFQGLVEYVQSAVGVPTNGDEPDNTNADEVSEEDNLAPSPSSSSSSTNLTEDSSLDQAETTTNISSYPGQTKTEKPAMPPASSKTLELSPSWVLEAFEESKRLTDHFIEQYRCANYVDTTLPKQTQLCVALTVEAFEQLGCPIRTAVAGQKLERIIHIPKHAQLAQYLYRLLSADARLIDLTEDGRITRTHMALPKPSDQILQDLLRLYPDHEWANRLAAFTGARLAEVLKGETDGLGLIFGTDEGRELVAGLYGDSLLNKLSYRQMEDIITRLASRIPRDSGPLKILEMGAGTGGTTKGMAPLLARLGIPVEYTFTDLSGSFVAAARKKYQKEYPFMKFQVHDIEKPPSDQLRHSQHIVIASNAIHATHSLTDSSRHVREFLKTDGFLMIVEMTQPVHWVDIIFGLFDGWWLFADGRDHAIASAGWWEKVFQSVGYGQVDWTDGHRPEVQIQRVIIAFASGPRYGRQPLPPAPPPNLVPGSHASRQAAVNEYLDKYTKGFTLPAQTSNPDISNSTSYWEKQCVLITGATGSLGVHLVAAVAALDDVQTVICLNRRSPMDPDLRQQQAFERRGILLEAASMSKIRVLQTDSSKPQLGLTDEVYSSLVTSTTHIIHNAWPMTGKRPLSGLEQQFQVMRNLLDLAAQCSSTRPANVPRIVFQFISSIATVGYYPLWSGQTLVPETCMGIESVLANGYGEAKYVCEQMLDRTLHQYPDRFRAMAVRLGQIAGSRTSGYWNPMEHLSFLFKSAQTLQVFPDFTGDLCWTPVNDVAATLSDLLLLSPHSSSMTDQPIYHIDNPVRQSWSEMVPVLIDALGIPAQNVFPFADWVCRVRAFPGQVEWDNPAALLIDFLDDHFLRMSCGGLLLDTKRACEHSPTLAAVGPVTAELARKYIQSWKEMGFLNP