ID   LEP_BUCAI               Reviewed;         314 AA.
AC   P57347;
DT   01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT   01-DEC-2000, sequence version 1.
DT   25-MAY-2022, entry version 124.
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; OrderedLocusNames=BU259;
OS   Buchnera aphidicola subsp. Acyrthosiphon pisum (strain APS) (Acyrthosiphon
OS   pisum symbiotic bacterium).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Erwiniaceae; Buchnera.
OX   NCBI_TaxID=107806;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=APS;
RX   PubMed=10993077; DOI=10.1038/35024074;
RA   Shigenobu S., Watanabe H., Hattori M., Sakaki Y., Ishikawa H.;
RT   "Genome sequence of the endocellular bacterial symbiont of aphids Buchnera
RT   sp. APS.";
RL   Nature 407:81-86(2000).
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:0000250}; Multi-pass membrane
CC       protein {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the peptidase S26 family. {ECO:0000305}.
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DR   EMBL; BA000003; BAB12969.1; -; Genomic_DNA.
DR   RefSeq; NP_240083.1; NC_002528.1.
DR   RefSeq; WP_009874213.1; NC_002528.1.
DR   AlphaFoldDB; P57347; -.
DR   SMR; P57347; -.
DR   STRING; 107806.10038934; -.
DR   MEROPS; S26.001; -.
DR   EnsemblBacteria; BAB12969; BAB12969; BAB12969.
DR   KEGG; buc:BU259; -.
DR   PATRIC; fig|107806.10.peg.269; -.
DR   eggNOG; COG0681; Bacteria.
DR   HOGENOM; CLU_028723_1_1_6; -.
DR   OMA; SDSRFWG; -.
DR   Proteomes; UP000001806; Chromosome.
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   Gene3D; 2.170.230.10; -; 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   InterPro; IPR019766; Sign_pep_all-beta_subdom.
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; Reference proteome;
KW   Transmembrane; Transmembrane helix.
FT   CHAIN           1..314
FT                   /note="Signal peptidase I"
FT                   /id="PRO_0000109503"
FT   TRANSMEM        5..25
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        26..63
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        64..84
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        85..314
FT                   /note="Extracellular"
FT                   /evidence="ECO:0000255"
FT   ACT_SITE        88
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        143
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   314 AA;  37023 MW;  B968E83705840780 CRC64;
     MANILTIFLL ISTLVTGIFW SFYCIKSFKN YLINKKIINN NNFHQEKIEK SKNKTYFLKS
     LASFFPIFLA IFIIRSFIYE PFQIPSGSMM PTLLVGDFIL VEKFSYGIKE PITHKILIRT
     KKPNRGDIAV FQHPTDHNIN YIKRIIGLPG DKIRYDLHDK HIHICTNYSD QRGCEKKISI
     NYSQSRSSNF IQKIYFSNKN NIKEDKNIYN SLYFDIVEEI IEDVKHSILL LNSIKNTKEN
     YFQQKNMPKL TWIVPKGEYF MMGDNRDNSL DSRYWGFVPE KNLVGKAIKI WMSFDKNENE
     WPTGIRINRI GSIH