Protein: Highly reducing polyketide synthase easB (HR-PKS easB) (EC 2.3.1.-) (Emericellamide biosynthesis protein B) (Q5BA83)
Organism: Emericella nidulans (strain FGSC A4 / ATCC 38163 / CBS 112.46 / NRRL 194 / M139) (Aspergillus nidulans)
Function: Polyketide synthase; part of the gene cluster that mediates the biosynthesis of emericellamides, secondary metabolites acting as antibiotics. The biosynthesis of emericellamides initiates from the highly reducing polyketide synthase easB which catalyzes the formation of the linear polyketide chain. EasB produces several polyketides that can be further processed by the downstream enzymes. The polyketides are released from easB as linear polyketide carboxylic acids, which are converted to CoA thioesters by the acyl-CoA ligase easD. The substrates are then loaded onto the acyltransferase easC, which shuttles them to the first thiolation (T) domain of the nonribosomal peptide synthetase easA. EasA then performs condensation of the polyketides with one glycine, two alanine, one valine and one leucine residues. A last step of cyclization leads to the production of emericellamides.
Interaction partners:
- Nonribosomal peptide synthetase easA
- Acyl-CoA ligase easD
Sequence:
MSPASRSRVEIADSESDSERLSSSPWSILSDNDSNTSDERSTRAGPGSLEPIAVIGIGCRLSGSATDVSGLWDMLKSGRSGWTPGPGTRFNMKAFQDPTGTRSGTTNATGGHFIREDISKFDATFFGINPVEAQAMDPQQRLMLEVAYEAFENAGITMDALWGSNTGVYVGQWASDYHEIATRDIERPPLYLVTGTGPAITSNRVSYVFNLRGPSFTVDTGCSSSLVALHQAVLSLRNRETTQCFVGGVNLLLDPQRFHYQSRLKMFSKDGRSFPFDARANGYGRGEGVTGVVLKPLSVALRDGDPVRAVIRNSVLNQDGRTPGISVPSAVAQKEAIIRAYRQAKLDLYADYVEAHGTGTKVGDPIETSAIAAALTQRRSPSRPLPIGSIKGNIGHTESAAGLAGLIKSVLMLENGMIPPQVNYETTNPDIHLEEWNLRIPTKLERQTLRRISLNSFGYGGTNAHVIIDAAHEAISAFGRLSLSRHLQLSYHSEKPRVFMVSGASEKACQRVCARLARYLVVNHRNSINPDALLARLAHTLAKQSIHAYRVIFVASELDELIKQLITASHSTITRREKFGQHRIALIFSGQGAQYAEMGRDLLKSYPSFVRSLERARQQLSRLGCTWDLLSELCRPKADSRVNEPAFSQPMCTAIQLALVDLLNEFGVSPSAVLGHSSGEIGAAYAAGALSFRDAISVSYYRGKLASELLAENQSPGAMIAVGAPPDIAEQHINKLGTDVGRMRIACFNSPSSVTVSGDVAAIDRIKEVLDTEGLFNRKLITHGAAYHSHQMKLIEDKYIAALKGLKAKPVSSSIRMFSSVTSKELDESTVLDGGYWAQNLVSPVLFSQALRTMCEQDYNGLPIDTLIEVGPHSQLSGPVNQILKTIPGPHGQASYTNTLKRGDDAETALLRCLGFLAIKNGSVRLCDLNKDSKDSDIQPLADLPPYSFDHDRSFWHETRLSRDYRHREHLPHELLGTLSADVNKLEPRWRRFVSLKETPWLRNHIIQGLITFPAAGYITMAIQAIRQHMHTANPASTIQFIRLRDVSFGKGLVLPDENAEVEISLSLRPQARTARESSGIWNEFRIFTVTPDQKWTEHCRGLVQAEVDSVEGFRSIFTPADISRIDSECTHGTIPQKFYAVGKRNGLDWQHPFNNLHQIRSSKHSCVATARVPEYEMPSGGMEDLLHPAVLDSALFHGLSTVIYLEDGRSSAYVPTFIKQLWVANRHVAPGSYLTCSTIRRNEPLVFDLHTKDEINQMAVVAQGIRVTSLGGDVAAGVSKREACHTQTLVPYVDAWTTEHRDQVCRATIELGSLMETNRALDAITIHFAQNAIREISLNDIQETHLQRYFQWMGTLADETYDNILLENKPEDLGVIGEAIAILGPHLVDILKGKTSALSLLTKNNLLSRVYTEWCSSRLYPQMSAYCHELGRFNPQLKVLEIGAGTGSATLPILKALNDCSGRFIQRYDFTDISPGFFEPAKERLGDLANVVEFRVLDAGRNAQEQGFEEGAYDLIVACNVIHATPRIDETLRNIRPLLKPGGKFMLMEISRYTLYFNIVFGLFEGWWLGYDEGRTRSPLLTDSEWCQRLEKAGFAHIEKAFVDYPHENGGSLSVFISTAPFPRRNESLPIHLLTDSNASNATEEQAQEIQQACQTSVALLPITHPCQHGGVAILLPEIAKLLCAEPDVNVWNSFKNWILKSRAVLLVSNCTMADSSHAETGLWAGFARTMRLEYPNLRQVVLDIQTPNVPVMSKLKEVLPIILNSSSFDLDCLSSEVENEFTEKDGQLFVSRYAYRPDISRDVDLTSRQAASEPVPFVSTGRILTAELGVPGLLETIRWKDDIECPPLGPDDVRFELRGASINFKDVLIAAGQLEGITEMRNDCSGVVVEVGENMKHRFKPGDRVCALYSRSYTNYPLVHGDCCQVIPDSLSFAEGASLPIVWATVYYGLVDKGSLSKGEKILIHSAAGAVGQAAIMLAQHLGAEVFATVGSEAKRDLLHAKYGVPYDHIFSSRTTAFYGEIMKSTGGYGVDVVLNSLSGEMFRESCNLMASFGRFVEIGRKDLMDDALMPMEFLLRNITFSYVDLTAIIEQRKPLARRLLHDIADLAASGSIRPVTLTTMPISDIEIAFRQIQAGKHTGKIVLTVEENQEVPAVPSMPKQARLHEDASYIVVGGLGGLGRWLTTWLADHGAKHIVALSRSGAKDADSRTFISNIRGRGVNLIAPPCDVVCADAVVALAQELKRSELPPVRGVINSAMVLRDTLFDNMTEDDWRTALASKVRGSQNLHTTFKSLDFFVMMSSIVAVRGNYGQSNYSAACSFQDTFVRHMVQQGEPAFSINIGPIRDVGYVSENPEVAEALRRNGLGSIGVSDVLIVLNHAILNARGANPSTCVASIGLIASDDESENGRDFLMTDRRFSQLVKHNGSKQKSAGEALDAITLLSAATQLDEAVHIVTNAILNQLSKLIVTPVEMLSPAQSLDSYGVDSLVAVELRNWIGAYLHANVQLMVIRGTGSISQLAAIVAKESRVVKL