ID SPAA_STRDO Reviewed; 1528 AA. AC P21979; DT 01-AUG-1991, integrated into UniProtKB/Swiss-Prot. DT 01-FEB-1996, sequence version 2. DT 28-JAN-2026, entry version 119. DE RecName: Full=Cell surface antigen I/II {ECO:0000303|PubMed:1855987}; DE AltName: Full=Surface protein antigen A {ECO:0000303|PubMed:1855987}; DE Contains: DE RecName: Full=Cell surface antigen II; DE Flags: Precursor; GN Name=spaA {ECO:0000303|PubMed:1855987}; OS Streptococcus downei (Streptococcus sobrinus). OC Bacteria; Bacillati; Bacillota; Bacilli; Lactobacillales; Streptococcaceae; OC Streptococcus. OX NCBI_TaxID=1317; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RC STRAIN=6715 / Serotype G; RX PubMed=1855987; DOI=10.1128/iai.59.8.2677-2685.1991; RA Lapolla R.J., Haron J.A., Kelly C.G., Taylor W.R., Bohart C., Hendricks M., RA Pyati J., Graff R.T., Ma J.K.-C., Lehner T.; RT "Sequence and structural analysis of surface protein antigen I/II (SpaA) of RT Streptococcus sobrinus."; RL Infect. Immun. 59:2677-2685(1991). RN [2] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 423-817. RX PubMed=1694526; DOI=10.1128/jb.172.7.3988-4001.1990; RA Goldschmidt R.M., Thoren-Gordon M., Curtiss R. III; RT "Regions of the Streptococcus sobrinus spaA gene encoding major RT determinants of antigen I."; RL J. Bacteriol. 172:3988-4001(1990). CC -!- SUBCELLULAR LOCATION: Secreted, cell wall {ECO:0000255|PROSITE- CC ProRule:PRU00477}; Peptidoglycan-anchor {ECO:0000255|PROSITE- CC ProRule:PRU00477}. CC -!- MISCELLANEOUS: Immunodominant determinants are located in the C- CC terminal two-thirds of the SpaA protein. CC -!- SIMILARITY: Belongs to the antigen I/II family. {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; X57841; CAA40973.1; -; Genomic_DNA. DR EMBL; M38210; AAA26977.1; -; Genomic_DNA. DR AlphaFoldDB; P21979; -. DR SMR; P21979; -. DR FunFam; 2.60.40.740:FF:000001; Major cell-surface adhesin PAc; 1. DR Gene3D; 2.60.40.740; -; 3. DR Gene3D; 6.10.250.2200; -; 4. DR Gene3D; 2.60.530.10; Major cell-surface adhesin PAc; 1. DR InterPro; IPR026345; Adh_isopep-form_adh_dom. DR InterPro; IPR041324; AgI/II_N. DR InterPro; IPR032300; Antigen_C. DR InterPro; IPR013574; Glucan-bd_C/Surface_Ag-I/II_V. DR InterPro; IPR019931; LPXTG_anchor. DR InterPro; IPR036234; SA_I/II_PAC_V_sf. DR InterPro; IPR009578; Surface_Ag_I_II_A_rpt. DR NCBIfam; TIGR04228; isopep_sspB_C2; 1. DR NCBIfam; TIGR01167; LPXTG_anchor; 1. DR NCBIfam; NF033804; Streccoc_I_II; 2. DR Pfam; PF18652; Adhesin_P1_N; 1. DR Pfam; PF17998; AgI_II_C2; 1. DR Pfam; PF16364; Antigen_C; 1. DR Pfam; PF08363; GbpC; 1. DR Pfam; PF00746; Gram_pos_anchor; 1. DR Pfam; PF06696; Strep_SA_rep; 2. DR SUPFAM; SSF74914; V-region of surface antigen I/II (SA I/II, PAC); 1. DR PROSITE; PS51965; AG_I_II_AR; 4. DR PROSITE; PS50847; GRAM_POS_ANCHORING; 1. PE 3: Inferred from homology; KW Cell wall; Peptidoglycan-anchor; Repeat; Secreted; Signal. FT SIGNAL 1..50 FT /evidence="ECO:0000255" FT CHAIN 51..? FT /note="Cell surface antigen I/II" FT /id="PRO_0000005666" FT CHAIN ?..1506 FT /note="Cell surface antigen II" FT /id="PRO_0000005667" FT PROPEP 1507..1528 FT /note="Removed by sortase" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00477" FT /id="PRO_0000005668" FT REPEAT 161..235 FT /note="Ag I/II A 1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01310" FT REPEAT 236..315 FT /note="Ag I/II A 2" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01310" FT REPEAT 316..396 FT /note="Ag I/II A 3" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01310" FT REPEAT 397..478 FT /note="Ag I/II A 4" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01310" FT REGION 50..156 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT REGION 840..951 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT REGION 1459..1480 FT /note="Disordered" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT MOTIF 1503..1507 FT /note="LPXTG sorting signal" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00477" FT COMPBIAS 51..68 FT /note="Low complexity" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 83..97 FT /note="Polar residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 124..133 FT /note="Polar residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 142..154 FT /note="Basic and acidic residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 855..879 FT /note="Basic and acidic residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT COMPBIAS 1459..1468 FT /note="Polar residues" FT /evidence="ECO:0000256|SAM:MobiDB-lite" FT MOD_RES 1506 FT /note="Pentaglycyl murein peptidoglycan amidated threonine" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00477" FT CONFLICT 427 FT /note="A -> E (in Ref. 2; AAA26977)" FT /evidence="ECO:0000305" FT CONFLICT 431 FT /note="Q -> K (in Ref. 2; AAA26977)" FT /evidence="ECO:0000305" FT CONFLICT 434 FT /note="Q -> K (in Ref. 2; AAA26977)" FT /evidence="ECO:0000305" FT CONFLICT 531 FT /note="A -> S (in Ref. 2; AAA26977)" FT /evidence="ECO:0000305" FT CONFLICT 600 FT /note="A -> S (in Ref. 2; AAA26977)" FT /evidence="ECO:0000305" SQ SEQUENCE 1528 AA; 165573 MW; B235F9CCD92838E0 CRC64; MLQKCKLEGI IICNEKRLLG AAKVKSGRTL SGALLGTAIL ASGAGQKALA EETSTTSTSG GDTAVVGTET GNPATNLPDK QDNPSSQAET SQAQARQKTG AMSVDVSTSE LDEAAKSPQE AGVTVSQDAT VNKGTVEPSD EANQKEPEIK DDYSKQAADI QKATEDYKAS VAANQAETDR INQEIAAKKA QYEQDLAANK AEVERSLMRM RKPRPIYEAK LAQNQKDLAA IQQANSDSQA AYAAAKEAYD KEWARVQAAN AAAKKAYEEA LAANTAKNDQ IKAEIEAIQQ RSAKADYEAK LAQYEKDLAA AQAGNAANEA DYQAKKAAYE QELARVQAAN AAAKQAYEQA LAANSAKNAQ ITAENEAIQQ NAQAKADYEA KLAQYQKDLA AAQSGNAANE ADYQEKLAAY EKELARVQAA NAAAKQAYEQ QVQQANAKNA EITEANRAIR ERNAKAKTDY ELKLSKYQEE LAQYKKDLAE YPAKLQAYQD EQAAIKAALA ELEKHKNEDG NLSEPSAQSL VYDLEPNAQV ALVTDGKLLK ASALDEAFSH DEKNYNNHLL QPDNLNVTYL EQADDVASSV ELFGNFGDKA GWTTTVSNGA EVKFASVLLK RGQSATATYT NLKNSYYNGK KISKVVYKYT VDPDSKFQNP TGNVWLGIFT DPTLGVFASA YTGQNEKDTS IFIKNEFTFY DEDGNPIDFD NALLSVASLN REHNSIEMAK DYSGTFVKIS GSSIGEKNGM IYATDTLNFK KGEGGSLHTM YTRASEPGSG WDSADAPNSW YGAGAVRMSG PNNYITLGAT SATNVLSLAE MPQVPGKDNT AGKKPNIWYS LNGKIRAVNV PKVTKEKPTP PVEPTKPDEP TYEVEKELVD LPVEPKYEPE PTPPSKNPDQ SIPEKPVEPT YEVEKELEPA PVEPSYEKEP TPPQSTPDQE EPEKPVEPSY QSLPTPPVEP VYETVPGPVS VPTVRYHYYK LAVQPGVTKE IKNQDDLDID KTLVAKQSTV KFQLKTADLP AGRPETTSFV LMDPLPSGYQ LNLEATKVAS PGFEASYDAM THTVTFTATA ETLAALNQDL TKAVATIYPT VVGQVLNDGA TYTNNFTLMV NDAYGIKSNI VRVTTPGKPN DPDNPSNNYI TPHKVNKNEN GVVIDGKSVL AGTTNYYELT WDLDQYKGDK SAKEIIQKGF FYVDDYPEEA LDLRTDLIKL TDANGKAVTG VSVADYASLE AAPAAVQDML KKANIIPKGA FQVFTADDPQ AFYDAYVVTG TDLTIVTPMT VKAEMGKTGG SYENRAYQID FGNGYESNLV VNNVPKINPE KDVTLTMDPA DSTNVDGQTI ALNQVFNYRL IGGIIPADHA EELFEYSFSD DYDQTGDQYT GQYKAFAKVD LTLKDGTIIK AGTDLTSYTE AQVDEANGQI VVTFKEDFLR SVSVDSAFQA EVYLQMKRIA VGTFANTYVN TVNGITYSSN TVRTSTPEPK QPSPVDPKTT TTVVFQPRQG KAYQPAPPAG AQLPATGDSS NAYLPLLGLV SLTAGFSC //