ID   LEP_PHOLA               Reviewed;         203 AA.
AC   Q51876;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   25-MAY-2022, entry version 101.
DE   RecName: Full=Signal peptidase I;
DE            Short=SPase I;
DE            EC=3.4.21.89;
DE   AltName: Full=Leader peptidase I;
GN   Name=lepB; Synonyms=lep;
OS   Phormidium laminosum.
OC   Bacteria; Cyanobacteria; Oscillatoriophycideae; Oscillatoriales;
OC   Oscillatoriaceae; Phormidium.
OX   NCBI_TaxID=32059;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=7865790; DOI=10.1007/bf00019191;
RA   Packer J.C.L., Andre D., Howe C.J.;
RT   "Cloning and sequence analysis of a signal peptidase I from the
RT   thermophilic cyanobacterium Phormidium laminosum.";
RL   Plant Mol. Biol. 27:199-204(1995).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Cleavage of hydrophobic, N-terminal signal or leader sequences
CC         from secreted and periplasmic proteins.; EC=3.4.21.89;
CC   -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000305}; Single-pass type II
CC       membrane protein {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the peptidase S26 family. {ECO:0000305}.
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DR   EMBL; X81990; CAA57518.1; -; Genomic_DNA.
DR   PIR; S51921; S51921.
DR   AlphaFoldDB; Q51876; -.
DR   SMR; Q51876; -.
DR   MEROPS; S26.008; -.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0004252; F:serine-type endopeptidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006465; P:signal peptide processing; IEA:InterPro.
DR   CDD; cd06530; S26_SPase_I; 1.
DR   InterPro; IPR036286; LexA/Signal_pep-like_sf.
DR   InterPro; IPR000223; Pept_S26A_signal_pept_1.
DR   InterPro; IPR019758; Pept_S26A_signal_pept_1_CS.
DR   InterPro; IPR019757; Pept_S26A_signal_pept_1_Lys-AS.
DR   InterPro; IPR019756; Pept_S26A_signal_pept_1_Ser-AS.
DR   InterPro; IPR019533; Peptidase_S26.
DR   PANTHER; PTHR43390; PTHR43390; 1.
DR   Pfam; PF10502; Peptidase_S26; 1.
DR   PRINTS; PR00727; LEADERPTASE.
DR   SUPFAM; SSF51306; SSF51306; 1.
DR   TIGRFAMs; TIGR02227; sigpep_I_bact; 1.
DR   PROSITE; PS00501; SPASE_I_1; 1.
DR   PROSITE; PS00760; SPASE_I_2; 1.
DR   PROSITE; PS00761; SPASE_I_3; 1.
PE   3: Inferred from homology;
KW   Cell membrane; Hydrolase; Membrane; Protease; Transmembrane;
KW   Transmembrane helix.
FT   CHAIN           1..203
FT                   /note="Signal peptidase I"
FT                   /id="PRO_0000109512"
FT   TOPO_DOM        1..33
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        34..50
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        51..203
FT                   /note="Extracellular"
FT                   /evidence="ECO:0000255"
FT   REGION          1..26
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        59
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        109
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   203 AA;  22485 MW;  887C4F9C93F5CD41 CRC64;
     MSSESDSPTP QTPPAQPAAS QPKADSPLME GIKTIGLSVV LALGIRTFVA EARYIPSESM
     LPTLEVNDRL IVEKISYHFN PPRRGDIIVF HPTEALKQQN PSLNEAFIKR VIGLPGETVQ
     VTGGRVLING QPLEENYIQS PPDYQWGPEK VPADSFLVLG DNRNNSYDSH FWGYVPRQNI
     IGRAVVRFWP VNRLGELGPP PSY