ID   SBI_STAAB               Reviewed;         436 AA.
AC   Q2YVZ4;
DT   10-FEB-2009, integrated into UniProtKB/Swiss-Prot.
DT   20-DEC-2005, sequence version 1.
DT   25-MAY-2022, entry version 87.
DE   RecName: Full=Immunoglobulin-binding protein Sbi;
DE   Flags: Precursor;
GN   Name=sbi; OrderedLocusNames=SAB2298;
OS   Staphylococcus aureus (strain bovine RF122 / ET3-1).
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Staphylococcaceae;
OC   Staphylococcus.
OX   NCBI_TaxID=273036;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=bovine RF122 / ET3-1;
RX   PubMed=17971880; DOI=10.1371/journal.pone.0001120;
RA   Herron-Olson L., Fitzgerald J.R., Musser J.M., Kapur V.;
RT   "Molecular correlates of host specialization in Staphylococcus aureus.";
RL   PLoS ONE 2:E1120-E1120(2007).
CC   -!- FUNCTION: Plays a role in the inhibition of both the innate and
CC       adaptive immune responses. Possesses two N-terminal domains that bind
CC       the Fc region of IgG and two domains that form a tripartite complex
CC       with complement factors C3b and CFH. By recruiting CFH and C3b, the
CC       secreted form acts as a potent complement inhibitor of the alternative
CC       pathway-mediated lysis. {ECO:0000250|UniProtKB:A6QJQ7}.
CC   -!- SUBUNIT: Interacts (via sbi-I and sbi-II domains) with the Fc region of
CC       mammalian immunoglobulin G (IgG) proteins. Interacts (via sbi-III and
CC       sbi-IV domains) with host complement C3. Interacts (via sbi-III and
CC       sbi-IV domains) with host CFH (By similarity). Interacts (via sbi-IV
CC       domain) with beta-2-glycoprotein 1/APOH (By similarity).
CC       {ECO:0000250|UniProtKB:A6QJQ7, ECO:0000250|UniProtKB:Q931F4}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:A6QJQ7}. Cell
CC       membrane {ECO:0000250|UniProtKB:A6QJQ7}. Note=Occurs both
CC       extracellularly and associated with the cytoplasmic membrane where only
CC       the domains I and II are exposed to the extracellular media. Membrane
CC       association occurs via binding to lipoteichoic acid.
CC       {ECO:0000250|UniProtKB:A6QJQ7}.
CC   -!- DOMAIN: Sbi-I and sbi-II domains provide protection only when anchored
CC       to the cell surface, whereas only the secreted sbi-III and sbi-IV
CC       domains are biologically active. {ECO:0000250|UniProtKB:A6QJQ7}.
CC   -!- SIMILARITY: Belongs to the immunoglobulin-binding protein Sbi family.
CC       {ECO:0000305}.
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DR   EMBL; AJ938182; CAI81987.1; -; Genomic_DNA.
DR   RefSeq; WP_000792550.1; NC_007622.1.
DR   AlphaFoldDB; Q2YVZ4; -.
DR   SMR; Q2YVZ4; -.
DR   KEGG; sab:SAB2298; -.
DR   HOGENOM; CLU_051343_0_0_9; -.
DR   OMA; NAHASEQ; -.
DR   PRO; PR:Q2YVZ4; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0019864; F:IgG binding; IEA:UniProtKB-KW.
DR   Gene3D; 1.10.10.1270; -; 1.
DR   InterPro; IPR009063; Ig/albumin-bd_sf.
DR   InterPro; IPR021657; IgG-binding_Sbi_dom_IV.
DR   InterPro; IPR003132; Protein_A_Ig-bd.
DR   InterPro; IPR041909; Sbi_C3_db_domIV.
DR   Pfam; PF02216; B; 2.
DR   Pfam; PF11621; Sbi-IV; 1.
DR   SUPFAM; SSF46997; SSF46997; 2.
PE   3: Inferred from homology;
KW   Cell membrane; IgG-binding protein; Membrane; Repeat; Secreted; Signal;
KW   Virulence.
FT   SIGNAL          1..29
FT                   /evidence="ECO:0000255"
FT   CHAIN           30..436
FT                   /note="Immunoglobulin-binding protein Sbi"
FT                   /id="PRO_0000361886"
FT   REPEAT          43..94
FT                   /note="B 1"
FT   REPEAT          95..148
FT                   /note="B 2"
FT   REPEAT          267..271
FT                   /note="2-1"
FT   REPEAT          272..276
FT                   /note="2-2"
FT   REPEAT          277..281
FT                   /note="2-3"
FT   REPEAT          282..286
FT                   /note="2-4"
FT   REPEAT          287..291
FT                   /note="2-5"
FT   REPEAT          292..296
FT                   /note="2-6"
FT   REPEAT          297..301
FT                   /note="2-7"
FT   REPEAT          302..306
FT                   /note="2-8"
FT   REGION          42..94
FT                   /note="Sbi-I"
FT   REGION          103..153
FT                   /note="Sbi-II"
FT   REGION          154..195
FT                   /note="Sbi-III"
FT   REGION          196..253
FT                   /note="Sbi-IV"
FT   REGION          267..306
FT                   /note="8 X 5 AA tandem repeat of P-[KQ]-[AISV]-[EKQ]-
FT                   [AKLSV]"
FT   REGION          268..295
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   436 AA;  50199 MW;  B6611C27CEA4EFC9 CRC64;
     MKNKYISKLL VGAATITLAT MISNGEAKAS ENTQQTSTKH QTTQNNYITD QQKAFYQVLH
     LKGITEEQRN QYIKTLREHP ERAQEVFSES LKDSKNPDRR VAQQNAFYNV LKNDNLTEQE
     KNNYIAQIKE NPDRSQQVWV ESVQSSKAKE RQNIENADKA IKDFQDNKAP HDKSAAYEAN
     SKLPKDLRDK NNRFVEKVSI EKAIVRHDER VKSANDAISK LNEKDSIENR RLAQREVNKA
     PMDVKEHLHK QLDALVAQKD AEKKVAPKVE APQIQSPQIE KPKAESPKVE VPQIQSPKVE
     VPQSKLLGYY QSLKDSFNYG YKYLTDTYKS YKEKYDTAKY YTDKYFKYKG TIDKTVQSVF
     GNGYKSYIQP LKVEDQKNYV SKSYAQVRNY VTETLNTGKV LYAFYQNPKL VNAAITTAET
     ATSIKNIFSS FTSFFK