ID   PPOCM_SPIOL             Reviewed;         531 AA.
AC   Q94IG7;
DT   04-JAN-2005, integrated into UniProtKB/Swiss-Prot.
DT   01-DEC-2001, sequence version 1.
DT   03-AUG-2022, entry version 79.
DE   RecName: Full=Protoporphyrinogen oxidase 2 {ECO:0000305};
DE            Short=Protox II {ECO:0000303|PubMed:11274159};
DE            EC=1.3.3.4 {ECO:0000269|PubMed:11274159};
DE   AltName: Full=SO-POX2 {ECO:0000303|PubMed:11274159};
DE   Flags: Precursor;
GN   Name=POX2 {ECO:0000303|PubMed:11274159};
OS   Spinacia oleracea (Spinach).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   Caryophyllales; Chenopodiaceae; Chenopodioideae; Anserineae; Spinacia.
OX   NCBI_TaxID=3562;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS L AND S), FUNCTION, CATALYTIC
RP   ACTIVITY, ALTERNATIVE INITIATION, SUBCELLULAR LOCATION, AND MUTAGENESIS OF
RP   MET-27.
RC   TISSUE=Leaf;
RX   PubMed=11274159; DOI=10.1074/jbc.m101140200;
RA   Watanabe N., Che F.-S., Iwano M., Takayama S., Yoshida S., Isogai A.;
RT   "Dual targeting of spinach protoporphyrinogen oxidase II to mitochondria
RT   and chloroplasts by alternative use of two in-frame initiation codons.";
RL   J. Biol. Chem. 276:20474-20481(2001).
CC   -!- FUNCTION: Catalyzes the 6-electron oxidation of protoporphyrinogen-IX
CC       to form protoporphyrin-IX. {ECO:0000269|PubMed:11274159}.
CC   -!- FUNCTION: Provides precursor for the mitochondrial and plastidic heme
CC       synthesis and the predominant chlorophyll synthesis in plastids.
CC       {ECO:0000269|PubMed:11274159}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=3 O2 + protoporphyrinogen IX = 3 H2O2 + protoporphyrin IX;
CC         Xref=Rhea:RHEA:25576, ChEBI:CHEBI:15379, ChEBI:CHEBI:16240,
CC         ChEBI:CHEBI:57306, ChEBI:CHEBI:57307; EC=1.3.3.4;
CC         Evidence={ECO:0000269|PubMed:11274159};
CC   -!- COFACTOR:
CC       Name=FAD; Xref=ChEBI:CHEBI:57692;
CC         Evidence={ECO:0000250|UniProtKB:O24164};
CC       Note=Binds 1 FAD per subunit. {ECO:0000250|UniProtKB:O24164};
CC   -!- PATHWAY: Porphyrin-containing compound metabolism; protoporphyrin-IX
CC       biosynthesis; protoporphyrin-IX from protoporphyrinogen-IX: step 1/1.
CC       {ECO:0000305}.
CC   -!- PATHWAY: Porphyrin-containing compound metabolism; chlorophyll
CC       biosynthesis. {ECO:0000305}.
CC   -!- SUBCELLULAR LOCATION: [Isoform L]: Plastid, chloroplast inner membrane
CC       {ECO:0000269|PubMed:11274159}; Peripheral membrane protein
CC       {ECO:0000305}; Stromal side {ECO:0000269|PubMed:11274159}.
CC   -!- SUBCELLULAR LOCATION: [Isoform S]: Mitochondrion inner membrane
CC       {ECO:0000269|PubMed:11274159}; Peripheral membrane protein
CC       {ECO:0000305}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative initiation; Named isoforms=2;
CC       Name=L; Synonyms=Protox IIL;
CC         IsoId=Q94IG7-1; Sequence=Displayed;
CC       Name=S; Synonyms=Protox IIS;
CC         IsoId=Q94IG7-2; Sequence=VSP_018805;
CC   -!- MISCELLANEOUS: [Isoform S]: Produced by alternative initiation at Met-
CC       27 of isoform S. Mitochondrial precursor. Contains a mitochondrial
CC       transit peptide from 1 to 22 which is removed in mature form.
CC       {ECO:0000305|PubMed:11274159}.
CC   -!- SIMILARITY: Belongs to the protoporphyrinogen/coproporphyrinogen
CC       oxidase family. Protoporphyrinogen oxidase subfamily. {ECO:0000305}.
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DR   EMBL; AB046993; BAB60710.1; -; mRNA.
DR   AlphaFoldDB; Q94IG7; -.
DR   SMR; Q94IG7; -.
DR   ChEMBL; CHEMBL2366509; -.
DR   UniPathway; UPA00251; UER00324.
DR   UniPathway; UPA00668; -.
DR   GO; GO:0009706; C:chloroplast inner membrane; IDA:UniProtKB.
DR   GO; GO:0005743; C:mitochondrial inner membrane; IDA:UniProtKB.
DR   GO; GO:0004729; F:oxygen-dependent protoporphyrinogen oxidase activity; IDA:UniProtKB.
DR   GO; GO:0015995; P:chlorophyll biosynthetic process; TAS:UniProtKB.
DR   GO; GO:0006783; P:heme biosynthetic process; TAS:UniProtKB.
DR   GO; GO:0006782; P:protoporphyrinogen IX biosynthetic process; IEA:UniProtKB-UniPathway.
DR   Gene3D; 3.50.50.60; -; 1.
DR   InterPro; IPR002937; Amino_oxidase.
DR   InterPro; IPR036188; FAD/NAD-bd_sf.
DR   InterPro; IPR004572; Protoporphyrinogen_oxidase.
DR   Pfam; PF01593; Amino_oxidase; 1.
DR   SUPFAM; SSF51905; SSF51905; 1.
DR   TIGRFAMs; TIGR00562; proto_IX_ox; 1.
PE   1: Evidence at protein level;
KW   Alternative initiation; Chlorophyll biosynthesis; Chloroplast; FAD;
KW   Flavoprotein; Heme biosynthesis; Membrane; Mitochondrion;
KW   Mitochondrion inner membrane; Oxidoreductase; Plastid;
KW   Plastid inner membrane; Porphyrin biosynthesis; Transit peptide.
FT   TRANSIT         1..48
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255"
FT   CHAIN           49..531
FT                   /note="Protoporphyrinogen oxidase 2"
FT                   /id="PRO_0000013327"
FT   BINDING         49..54
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250|UniProtKB:O24164"
FT   BINDING         72..73
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250|UniProtKB:O24164"
FT   BINDING         94..97
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250|UniProtKB:O24164"
FT   BINDING         294
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250|UniProtKB:O24164"
FT   BINDING         501..503
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250|UniProtKB:O24164"
FT   VAR_SEQ         1..26
FT                   /note="Missing (in isoform S)"
FT                   /evidence="ECO:0000305|PubMed:11274159"
FT                   /id="VSP_018805"
FT   MUTAGEN         27
FT                   /note="M->I: Targeted to chloroplasts only, due to lack of
FT                   alternative initiation."
FT                   /evidence="ECO:0000269|PubMed:11274159"
SQ   SEQUENCE   531 AA;  58320 MW;  4D4F900EDCB36C12 CRC64;
     MVILPVSQLS TNLGLSLVSP TKNNPVMGNV SERNQVNQPI SAKRVAVVGA GVSGLAAAYK
     LKSNGLNVTL FEADSRAGGK LKTVVKDGLI WDEGANTMTE SDEEVTSLFD DLGIREKLQL
     PISQNKRYIA RDGLPVLLPS NPVALLKSNI LSAKSKLQIM LEPFLWKKHN GAKVSDENAQ
     ESVAEFFERH FGKEFVDYLI DPFVAGTSGG DPQSLSMRHA FPELWNIENR FGSVISGFIQ
     SKLSSKKEKG GEKQSSNKKP RVRGSFSFQG GMQTLVDTIC KEFGEDELKL QSEVLSLSYS
     HNGSLTSENW SVSSMSNSTI QDQPYDAVVV TAPINNVKEL KIMKVENPFS LDFIPEVSCL
     PLSVIITTFK KTNVKRPLEG FGVLVPSNEQ HNGLKTLGTL FSSMMFPDRA PSDVYLYTTF
     VGGSRNRELA KASTDELKQI VSSDLQQLLG TEGEPTFVNH FYWSKAFPLY GRNYDSVLRA
     IEKMERDLPG LFYAGNHKGG LSVGKSIASG YKAAELAISY LESNKMTEET I