PYIB_MAGGR
ID PYIB_MAGGR Reviewed; 504 AA.
AC A0A4P8WAJ7;
DT 22-APR-2020, integrated into UniProtKB/Swiss-Prot.
DT 31-JUL-2019, sequence version 1.
DT 03-AUG-2022, entry version 9.
DE RecName: Full=Acetyltransferase pyiB {ECO:0000303|PubMed:31099577};
DE EC=2.3.1.- {ECO:0000305|PubMed:31099577};
DE AltName: Full=Pyrichalasin H biosynthesis cluster protein B {ECO:0000303|PubMed:31099577};
DE Flags: Precursor;
GN Name=pyiB {ECO:0000303|PubMed:31099577};
OS Magnaporthe grisea (Crabgrass-specific blast fungus) (Pyricularia grisea).
OC Eukaryota; Fungi; Dikarya; Ascomycota; Pezizomycotina; Sordariomycetes;
OC Sordariomycetidae; Magnaporthales; Pyriculariaceae; Pyricularia.
OX NCBI_TaxID=148305;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, DISRUPTION PHENOTYPE, AND
RP PATHWAY.
RC STRAIN=NI980;
RX PubMed=31099577; DOI=10.1021/acs.orglett.9b01344;
RA Wang C., Hantke V., Cox R.J., Skellam E.;
RT "Targeted gene inactivations expose silent cytochalasans in Magnaporthe
RT grisea NI980.";
RL Org. Lett. 21:4163-4167(2019).
RN [2]
RP FUNCTION.
RX PubMed=31644300; DOI=10.1021/acs.orglett.9b03372;
RA Wang C., Becker K., Pfuetze S., Kuhnert E., Stadler M., Cox R.J.,
RA Skellam E.;
RT "Investigating the function of cryptic cytochalasan cytochrome P450
RT monooxygenases using combinatorial biosynthesis.";
RL Org. Lett. 21:8756-8760(2019).
RN [3]
RP FUNCTION.
RX PubMed=32039410; DOI=10.1039/c9cc09590j;
RA Hantke V., Skellam E.J., Cox R.J.;
RT "Evidence for enzyme catalysed intramolecular [4+2] Diels-Alder cyclization
RT during the biosynthesis of pyrichalasin H.";
RL Chem. Commun. (Camb.) 56:2925-2928(2020).
CC -!- FUNCTION: Acetyltransferase; part of the gene cluster that mediates the
CC biosynthesis of the mycotoxin pyrichalasin H, a tyrosine-derived
CC cytochalasan that inhibits the growth of rice seedlings, but also
CC inhibits lymphocyte capping and actin polymerization and alters cell
CC morphology (PubMed:31099577) (Probable). Pyrichalasin H is indicated as
CC the responsible agent for the genus-specific pathogenicity of M.grisea
CC toward crabgrass (PubMed:31099577). The first step in the pathway is
CC catalyzed by the O-methyltransferase pyiA which methylates free
CC tyrosine to generate the precursor O-methyltyrosine (PubMed:31099577).
CC The hybrid PKS-NRPS pyiS, assisted by the enoyl reductase pyiC, are
CC responsible for fusion of the O-methyltyrosine precursor and the
CC polyketide backbone (PubMed:31099577). The polyketide synthase module
CC (PKS) of pyiS is responsible for the synthesis of the polyketide
CC backbone and the downstream nonribosomal peptide synthetase (NRPS)
CC amidates the carboxyl end of the polyketide with the O-methyltyrosine
CC precursor (PubMed:31099577). As the NRPS A-domain demonstrates
CC substrate tolerance, pyiS can also use phenylalanine, tyrosine and even
CC para-chlorophenylalanine as amino acid precursor, which leads to the
CC production of novel cytochalasans, including halogenated cytochalasans
CC (PubMed:31099577). Because pyiS lacks a designated enoylreductase (ER)
CC domain, the required activity is provided the enoyl reductase pyiC
CC (PubMed:31099577). Reduction by the hydrolyase pyiE leads to 1,5-
CC dihydropyrrolone, which is substrate for dehydration and intra-
CC molecular Diels-Alder cyclization by the Diels-Alderase pyiF to yield
CC the required isoindolone-fused macrocycle (PubMed:32039410). The
CC tailoring cytochrome P450 monooxygenases piyD and piyG catalyze the
CC hydroxylation at C-18 and C-7, respectivily, whereas the short-chain
CC dehydrogenase/reductase pyiH reduces the carbonyl at C-21 in
CC preparation for the transfer of an acetyl group by the
CC acetyltransferase pyiB (PubMed:31099577). These 3 reactions whose order
CC is not clear yet, lead to the production of O-methylpyrichalasin J, a
CC deacetylated pyrichalasin H (PubMed:31099577). Finally, pyiB to
CC converts O-methylpyrichalasin J into the final product pyrichalasin H
CC via acetylation of C-21 (PubMed:31099577).
CC {ECO:0000269|PubMed:31099577, ECO:0000269|PubMed:32039410,
CC ECO:0000305|PubMed:31644300}.
CC -!- PATHWAY: Mycotoxin biosynthesis. {ECO:0000305|PubMed:31099577}.
CC -!- DISRUPTION PHENOTYPE: Leads to the loss of pyrichalasin H production,
CC but still produces deacetylated pyrichalasin H.
CC {ECO:0000269|PubMed:31099577}.
CC -!- SIMILARITY: Belongs to the plant acyltransferase family. {ECO:0000305}.
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DR EMBL; MK801691; QCS37519.1; -; Genomic_DNA.
DR AlphaFoldDB; A0A4P8WAJ7; -.
DR SMR; A0A4P8WAJ7; -.
DR Proteomes; UP000515153; Genome assembly.
DR GO; GO:0016746; F:acyltransferase activity; IEA:UniProtKB-KW.
DR Gene3D; 3.30.559.10; -; 2.
DR InterPro; IPR023213; CAT-like_dom_sf.
PE 3: Inferred from homology;
KW Acyltransferase; Glycoprotein; Reference proteome; Signal; Transferase.
FT SIGNAL 1..18
FT /evidence="ECO:0000255"
FT CHAIN 19..504
FT /note="Acetyltransferase pyiB"
FT /id="PRO_0000449449"
FT ACT_SITE 181
FT /note="Proton acceptor"
FT /evidence="ECO:0000250|UniProtKB:Q70PR7"
FT CARBOHYD 84
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00498"
FT CARBOHYD 413
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00498"
FT CARBOHYD 467
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00498"
SQ SEQUENCE 504 AA; 56597 MW; 124A016D153616C6 CRC64;
MGFLSAGGLW ASLFRARISP IVETDEVLPL TLIDNIAAAR NAILSEVIRF DQVLDVVKLR
DGLTELIDKR GWRKLGGRLR LRPNGSLEIH VPREFTEERP AFRFTSQAFD IAIEEHALGS
QLPKLSDGPS LQPGSTSVDK FNLIPDKPEK LDDYVYSDRP ILALHVTSFT NSCIVTLTWS
HVVFGARGIK ELIAAWSKVL HGEQNVPLLL GTHQDVLAGI GTDGDKTAPF LLDPIKIKGL
GLVRIIFGLL WEIWQHPTVE TRALHLPKRF VSQLRQKCME ELGAFCREDP APFISEGDVL
EAWCSRFVAQ ARADEKPALV TNALDIKDRL TAPWSSRGEY LQNTGCCTWT PVQPETLLRS
PLGELAYVIR RSIQELATDD QLRAQLRIFR SLGHTKMLPL FGNPNSRVIS FSNWTKFNLF
EVTNLGPAVI STSPSTRSDA STSPIGRPVY MHCEAAGDSR MLRNCFNVTG KDWDGSYWIT
AHLYPEDWTK LEEYMRQTQQ HISD
