The following text describes a protein:
Function:
Hybrid PKS-NRPS synthetase; part of the gene cluster that mediates the biosynthesis of aspyridones. The polyketide-amino acid backbone preaspyridone A is first assembled by the PKS-NRPS hybrid apdA. The assembly of preaspyridone A is initiated by loading of malonyl-CoA onto apdA, followed by decarboxylation to yield the acetyl starter unit. The growing polyketide chain then elongates into a tetraketide. The adpA PKS module catalyzes three Claisen condensations, as well as beta-keto processing and methylation. Alpha-methylation step during polyketide synthesis is a prerequisite and a key checkpoint for chain transfer between PKS and NRPS modules. The downstream NRPS module contains the condensation (C), adenylation (A), and thiolation (T) domains and catalyzes the incorporation of tyrosine via the formation of the L-tyrosinyl-thioester and the amide linkage between L-tyrosinyl-thioester and the tetraketide. The bimodular assembly line is terminated with a reductase (R) domain that facilitates formation and release of the tetramic acid product. Because apdA lacks a designated enoylreductase (ER) domain, the required activity is provided the enoyl reductase apdC. ApdC appears to operate with different stereoselectivity in different PKS cycle (Ref.5). Combined with apdC, apdA is proposed to synthesize preaspyridone A via about 20 enzymatic steps. A number of oxidative steps performed successively by the cytochrome P450 monooxygenases apdE and apdB are required for the conversion of preaspyridone A to aspyridone A. The cytochrome P450 monooxygenase apdE is responsible for the oxidative dephenylation of preaspyridone A (Ref.5). Finally, the predicted FAD-dependent monooxygenase apdD and the acyl-CoA dehydrogenase apdG may be involved in the transformation of aspyridone A into aspyridone B (Probable).
Domain:
ApdA has the following domain architecture: KS-MAT-DH-MT-KR-ACP-C-A-T-R (Probable). The apdA PKS module (domains KS to ACP) is responsible for the biosynthesis of the polyketide chain and catalyzes three Claisen condensations, as well as beta-keto processing and methylation. The downstream NRPS module contains the condensation (C), adenylation (A), and thiolation (T) domains and catalyzes the formation of the L-tyrosinyl-thioester and the amide linkage between L-tyrosinyl-thioester and the tetraketide. The bimodular assembly line is terminated with a putative reductase (R) domain that facilitates formation and release of the tetramic acid product.
Sequence:
MQDLIAIVGSACRFPGQSDSPSKLWTRLKEPIDLRKTFPPQRLNLARFYHPDGEHHGSTDVRGTSYLLSEDPRQFDASFFNINPREAEGMDPQQRLLLETAFEALEAAGYSLEAMNGSKTSVHVGVMNSDFSNIQLRDPEVLPTYNATGTAISILSNRLSYFFNLKGPSVTIDTACSSSLVALHQAVQGLRAGDATAAIVAGANLIFDPAMYIAESSLHMLSPDSCSRMWDKDANGYARGEGVGVLVLKPLSRAIMDGDHVEAVIRSTGVNSDGRTKGITMPNAESQTELIRQTYRDAGLDPIRDRCQYFECHGTGTATGDPIEARAVHDAFFPTETRTASNTLIPDGKLYVGSVKTIIGHLEGCAGIAGVLKAVLAIKNRTIPPNMHFHEPNPRVIPFCDRLEIPTVPIPWPDTGRSPLRASINSFGFGGTNAHAIIEGYDALSSPVREATITPDDLFIGPLLFSANSSSSLVANVKNMAERIRSDPSIDLESLVWTLYARRSVLPVKAFFTGGTVQRLLNFMDRFVAESEETTSSTAGIKYQPLNPTETPGILGIFTGQGAQWALMGFSLLQQNHVFRAAIERCQAALATLHDSPSWSLLDELVKGADESRIGEAALSQPLCTALQIGLVDMLHSAGIKLDAVVGHSSGEIAAVYAAGIINADAAIKIAYYRGYYAKLAAGARGQAGRMMATAMSFDEAEEFCAQPQWRGRLAAAASNSPQSVTLSGDIDAIEEALQLFEAEKKFARILRTDTAYHSHHMQPCAERYLKSLQACQIKVSPPRKDCVWISSVRGDTQLLEGDLSTLADQYWVDNMCNPVLFSQAVETSIWNGGPFDVAVELGPHPALKGPVEQTIKAVYGPIPAYAGLMRRGDNEIEAFSGGVGFVWSRLGPDYVDMSGYRKGFIGADRLRPQVLKDLPVYCWDHSKLYWKESRISRQYRLRQDTPHELLGRRVPDDSDDSRRWRNVLRLSELPWIRGHVFQGQVLFPGAGYVAMALEAARELTEGRPATLFEIENVSLRRALVISEQAGIETAFTARVIDAKEGRNDTNRLEADFACYFCSAEGNEPLVKACTGRLIINYGDPAAEALPQRTRLPSNNVPVDMGRFYDAMNSVGLDYQGIFRGLVHGKRSLGCSSVKAAWGEDMQIDNYVVNPGFLDVAFQSVYTAFSSPASGEIWAPYLPIHIERLAVNPNVSYRSAKDEVQMEADAFVTVSNSTLLKGDIQLYQIDSQHAAIQVEGISMKSMSEPQPENDRCLFSETVWGPDVSLGVSEVTSRATEDDTPLVEALDRVSLFYWQNLLQEVGAEEIAQFQWYHQRMFDAVRFQVSSVRSGQHPIAKPEWLEDDWETILAVSEPYASRVDMRLIHAVGENLASVVREDTQLLEVMVQDDMLNRFYMEGYGFSVINNAVSDALEQITFKYPHANILEIGAGTGGTTRSILDRIGSRYGSYTYTDISPAFFEAAAEKFEDAREKIQFKVLDVEKEVGAQGFDEHGYDVIVAANVLHATRKLEETMKNARALLKPGGYLVLMEITGPDVLRTQFIMGGLPGWWYGVDDGRVLSPAISAQQWNQLLLDTGFSGLDCLAPDMLDEYKHSFSLMVSQAIDEKIQMLRDPVLSKTLLPAADVLIIGGRTHSNVIHEIRRYLSAWTSRVEVWDRIQTKQLDQLAEFENIICLEELDQPLFSTTMTSETLLALQKVLSGTKNVVWAINSAKSQNPHVNMTVGLGRAMRTEVPGLNLLFVDIDAVENPIACAQLLSQMLLQLRTGSLTAAENTLWAAELEIRVQDGRRLIPRVLPMTQMNETYNASRRVISKPVDIETTCVKMEDSAGSLRLVPGACMVDGPVQRGHNRLRIHRSLPLAFGGGTPCYLCSGDLRENGLPALALSTSNANLADIPNDMVFALDQDQPCDAAMLEATGRQLLARDICNRLPASNRILVYQPSHDFAQALLLTGRHFSFVSADKASCFSDWVYIHSRASRRAIQSRLPKDFDALIDCTGELPENLIACLSRNCRVLNMTLHQLDGSLLGPAYSAALAHVSSSSIGPSIRVKDLPLATPSKLPMVDWTGVDTVELTLQPLSMRKLFSSSATYLLAGMTGDLGLSLCRWMIDNGARNIALTSRNPNVGEELLQDMRRSGADIRVFRNDITDQNAVRTLVENIRLSMPPIAGVFNACMVLRDGLFSEMDVDTLNDPLAPKVDGSKILDDIFQDDSLDFFVLFSSLASIIGNAANPTTTLQTCSSLVLPPTAARRVWQPSPHNSSRQHEIILGLEPFIDSPNATKRPPWEHNPMFSHYVSRPLLQETPAATTVEAAADVKQLLRSTVSGEAVIPIVQEAFARKLESMMQLPANSINLNVPLIDLGCDSLLAIEIRRWFIKELGIDVPVLKVLSGDTTAQICEDAVRQFLALQLEKQDTVAPNMTEKPETKSHPSSNATIIDNDALDKADAANGDYESSSQGDDSRGNSSSSSSHTSPSIQATTPDIKPNTPVPLDVDADPLGRGFQRTMIRAEPASFAQSRLWFLTQYLHDPTTYNVTVRYDVRGNLPASRIVSSLNRTICHHQSLQTCFFMDSDKETLMQGVLSPSYSSIKHIPSGSEQTVREEYNRLRSRVWDLQKGETFAVTVVSLSPEQHTIIFGYHHIVMDGVSWHLFLRDLDLAYRLRPLPSIEMEYIDWSKKQFQSAQRGDFTRPLEYWRKQHSPPPSVMPLLPMAQTSSRKPLTSYDSHVISVQIDRQLVSHIRLVSQSLGVTPFHFHLAVIQSILCRLLKTEDLCIGVVDANRTSEAHSGTVGFFLNLLPVRFTTREHSTFQDLVSSTKRTILGAISNSEAPFDLILEDLKVLRSIEHSPLFQVAVNYRMGAMLQVPLGDGTMEVAAADDAKNPYDLSFGITETSTGTCLLELTSQKQLYTEQSTELLLQMYMDVLRASSDNPSLPVNQLPVTLEPSTGKALAVAKGPRAEYSWPNTLWERYDAIRKSFPEETAIKDGKSELSYSQLTRSVEKLAAMLISQGVTAGDSVGVLLHPSIDAIACMLALLRVGCIYTPLDTRLPVARLSIIVNRSKSSLVLYHASTHDVALELGKFSKLANVEDMCESGQAQVPAIAPQSNPASFLFYTSGSTGTPKGILLSQQNFVNHLAAKTDKLNLGREVVLQQSSLGFDMSVVQTFCALGNGGTLVIAPKEARGDPIALSTIMAKERVTLTIATPSEYSLLLRFGLEQLQRPYSWRHACMGGEVVSRQLVQQFCQLDHPDLQLTNCYGPTEITAAATFQDISLQMKDQSTTDGSLVGKALPNYSVYIMDASSGSPVPIGVTGEICIGGAGVSLGYLNSLEQTDAKFVRDPFASPEDITRGWTKMYRTGDMGCLTEDGTLIFMGRMDGDNQVKLNGLRIELDEIANSILTTGNDLVSEAVVTVHSGSGSGSPLLVAHVVPLGDNVDNSRLQQLARDLPLPQYMLPSVVVSLDRLPINANGKVDRKAIMALPLPTQRTESAAGTGTDTARHLSLAEGELRLLWEKVLPASGGPSRLDADSDFFMRGGTSMLLVRLQGAIKESIGVSIPVAELYQFPTLGQMARRISRRKEDHQASHATVINWDSETALTQDLIYAAKNQFSTRQTKAHDRQDILLTGSTSFLGKNILQSLLHNPLVERVHCVAVPAEDIPRLPASEKISIYTGSLLTPSLGLTKTEIAVLQSSLDVIIHAGSTGHCLNNYSSLRASNVDSTKFLAAIALLCRIPIHFISSNRVTLLSGSTSLPPASVSSSLPNTDGSEGFTASKWASERLLESVANLASGLPVTIHRPCAVFGEEAPNEDALNALLKYSKLTRCVPRFENFEGYLDFEDVHRVAATIAADALSAESRESKSAARVRHHSSGHKVSMKDFKGRMETLFACPFKEVSMAEWTERALQAGIDPLITGYLEAMTMKGEIIRFPYMGEAGSL