ID   NTNI_NECSZ              Reviewed;         734 AA.
AC   A0A455LRW3;
DT   02-JUN-2021, integrated into UniProtKB/Swiss-Prot.
DT   05-JUN-2019, sequence version 1.
DT   25-MAY-2022, entry version 12.
DE   RecName: Full=Terpene cyclase/mutase ntnI {ECO:0000303|PubMed:29797385};
DE            EC=5.4.99.- {ECO:0000305|PubMed:29797385};
DE   AltName: Full=Nectripenoid biosynthesis cluster protein I {ECO:0000303|PubMed:29797385};
GN   Name=ntnI {ECO:0000303|PubMed:29797385};
OS   Nectria sp.
OC   Eukaryota; Fungi; Dikarya; Ascomycota; Pezizomycotina; Sordariomycetes;
OC   Hypocreomycetidae; Hypocreales; Nectriaceae; Nectria.
OX   NCBI_TaxID=1755444;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, AND PATHWAY.
RC   STRAIN=Z14-w;
RX   PubMed=29797385; DOI=10.1002/anie.201804317;
RA   Zhang X., Wang T.T., Xu Q.L., Xiong Y., Zhang L., Han H., Xu K., Guo W.J.,
RA   Xu Q., Tan R.X., Ge H.M.;
RT   "Genome mining and comparative biosynthesis of meroterpenoids from two
RT   phylogenetically distinct fungi.";
RL   Angew. Chem. Int. Ed. 57:8184-8188(2018).
CC   -!- FUNCTION: Terpene cyclase/mutase; part of the gene cluster that
CC       mediates the biosynthesis of the meroterpenoids nectripenoids A and B,
CC       as well as cochliquninone D and isocochliquninone E (PubMed:29797385).
CC       The pathway probably begins with the HR-PKS ntnH that catalyzes two
CC       chain-extension steps to form a reduced triketide, which then primes
CC       the SAT domain in the NR-PKS ntnG to initiate three more cycles of
CC       extension to give a linear hexaketide corresponding to the polyketide
CC       part of nectripenoids (Probable). The FAD-dependent monooxygenase ntnJ
CC       then performs an oxidative decarboxylation at C11 of the ntnH/ntnG
CC       product, via an electrophilic aromatic hydroxylation with concomitant
CC       ipso-decarboxylation (Probable). The membrane-bound polyprenyl
CC       transferase ntnF then introduces a farnesyl group before the FAD-
CC       dependent monooxygenase ntnK functions as the first epoxidase on
CC       terminal C12'-C13' olefin, followed by a second epoxidation on C7'-C8'
CC       catalyzed by ntnA (Probable). The terpene cyclase/mutase ntnI then
CC       initiates the sequential tricyclic ring formation through protonation
CC       of the terminal epoxide and catalyzes the regioselective and
CC       stereoselective 6/6/6-tricyclic ring formation (Probable). The
CC       cytochrome P450 monooxygenase ntnM may then hydroxylate C1' (Probable).
CC       {ECO:0000269|PubMed:29797385, ECO:0000305|PubMed:29797385}.
CC   -!- PATHWAY: Secondary metabolite biosynthesis; terpenoid biosynthesis.
CC       {ECO:0000305|PubMed:29797385}.
CC   -!- SIMILARITY: Belongs to the terpene cyclase/mutase family.
CC       {ECO:0000305}.
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DR   EMBL; MH183002; AYO60869.1; -; mRNA.
DR   AlphaFoldDB; A0A455LRW3; -.
DR   SMR; A0A455LRW3; -.
DR   UniPathway; UPA00213; -.
DR   GO; GO:0005811; C:lipid droplet; IEA:InterPro.
DR   GO; GO:0016866; F:intramolecular transferase activity; IEA:InterPro.
DR   GO; GO:0016104; P:triterpenoid biosynthetic process; IEA:InterPro.
DR   CDD; cd02892; SQCY_1; 1.
DR   InterPro; IPR032696; SQ_cyclase_C.
DR   InterPro; IPR032697; SQ_cyclase_N.
DR   InterPro; IPR018333; Squalene_cyclase.
DR   InterPro; IPR008930; Terpenoid_cyclase/PrenylTrfase.
DR   PANTHER; PTHR11764; PTHR11764; 1.
DR   Pfam; PF13243; SQHop_cyclase_C; 1.
DR   Pfam; PF13249; SQHop_cyclase_N; 1.
DR   SUPFAM; SSF48239; SSF48239; 2.
DR   TIGRFAMs; TIGR01787; squalene_cyclas; 1.
PE   2: Evidence at transcript level;
KW   Isomerase; Repeat.
FT   CHAIN           1..734
FT                   /note="Terpene cyclase/mutase ntnI"
FT                   /id="PRO_0000452569"
FT   REPEAT          130..172
FT                   /note="PFTB 1"
FT                   /evidence="ECO:0000255"
FT   REPEAT          493..534
FT                   /note="PFTB 2"
FT                   /evidence="ECO:0000255"
FT   REPEAT          570..610
FT                   /note="PFTB 3"
FT                   /evidence="ECO:0000255"
FT   REPEAT          619..668
FT                   /note="PFTB 4"
FT                   /evidence="ECO:0000255"
FT   REGION          1..26
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        1..15
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   SITE            396
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
FT   SITE            453
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
FT   SITE            591
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250|UniProtKB:P48449"
SQ   SEQUENCE   734 AA;  83390 MW;  A264F8B1945EAEED CRC64;
     MQSHIGQWTS TAKGHLSRDE NGDEKTDYSR WRLVDRQGRQ TWRYLESDEE NEKSPQTVPE
     KYFLGLDTGL PDLPKAETPL QAAQDGVSFL SQLQLSSGQW ASECTGPMFI LPCVIIAWYV
     TNTPIPPAYA IEIRRYLFAR QRVEDGGWGW HVEARSSAIG TALNYVVLRL LGASKDDHRL
     IQARKLLHSY GGATYAPGIA KFWLCVLGVM KWECVNPFLP EFWLLPDSDP TAPSKWYIHT
     RTNFTSLSYI WSKQWSFAGD EVTKQLQTEL YPEPYSAIDF AAHRTSLAEV DNNYPKWWLV
     NLMNWLTVAV YIPYMRKKAT VESAEQRVWE LIQAEDKNSE FIGLSPISKA ANMIACYIHD
     GKDSESVRSH GETIFQYFWM NGEGMACNLS DGIQVWDTSL AVQAIAAAGG AGNPRFQSTV
     IKAHEFLEDH QLLDDVQDQE MCCRGHRKGG WPFSTKYQGY MISECTGEGL RSILQLQKTF
     QLDLKKRIPA DRLHNAVDCL LNLQNDTGGF GVYEKRQGSL KLAWLEMGEF SGKTMVTYDY
     VECTTAVVSA LASFSEFYPD YRKEEVQTAR TRGLEFIKSS QKPYGGWHGA WGVCFTYAGM
     FALESLALAG ETYSNSEPSR KGCTFLVSKQ RDDGGWGESY LSFQKEEYIE HEDAQVVQTA
     WACLGLMHAE YPDKTPVKRG LKLIMSRQQS KGHWLQEQYE GGVGDGVISY SNYKLYWPVR
     ALAEYVRRFG NEEM