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Entry version 105 (02 Jun 2021)
Sequence version 2 (01 Feb 1996)
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Protein

Cell surface antigen I/II

Gene

spaA

Organism
Streptococcus downei (Streptococcus sobrinus)
Status
Reviewed-Annotation score:

Annotation score:2 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
-Protein inferred from homologyi <p>This indicates the type of evidence that supports the existence of the protein. Note that the 'protein existence' evidence does not give information on the accuracy or correctness of the sequence(s) displayed.<p><a href='/help/protein_existence' target='_top'>More...</a></p>

<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni

Miscellaneous

Immunodominant determinants are located in the C-terminal two-thirds of the SpaA protein.

<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi

<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.<p><a href='/help/protein_names' target='_top'>More...</a></p>Protein namesi
Recommended name:
Cell surface antigen I/II1 Publication
Alternative name(s):
Surface protein antigen A1 Publication
Cleaved into the following chain:
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section indicates the name(s) of the gene(s) that code for the protein sequence(s) described in the entry. Four distinct tokens exist: 'Name', 'Synonyms', 'Ordered locus names' and 'ORF names'.<p><a href='/help/gene_name' target='_top'>More...</a></p>Gene namesi
Name:spaA1 Publication
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section provides information on the name(s) of the organism that is the source of the protein sequence.<p><a href='/help/organism-name' target='_top'>More...</a></p>OrganismiStreptococcus downei (Streptococcus sobrinus)
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section shows the unique identifier assigned by the NCBI to the source organism of the protein. This is known as the 'taxonomic identifier' or 'taxid'.<p><a href='/help/taxonomic_identifier' target='_top'>More...</a></p>Taxonomic identifieri1317 [NCBI]
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section contains the taxonomic hierarchical classification lineage of the source organism. It lists the nodes as they appear top-down in the taxonomic tree, with the more general grouping listed first.<p><a href='/help/taxonomic_lineage' target='_top'>More...</a></p>Taxonomic lineageiBacteriaFirmicutesBacilliLactobacillalesStreptococcaceaeStreptococcus

<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi

<p>UniProtKB Keywords constitute a <a href="http://www.uniprot.org/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='/help/keywords' target='_top'>More...</a></p>Keywords - Cellular componenti

Cell wall, Secreted

<p>This section describes post-translational modifications (PTMs) and/or processing events.<p><a href='/help/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'PTM / Processing' section denotes the presence of an N-terminal signal peptide.<p><a href='/help/signal' target='_top'>More...</a></p>Signal peptidei1 – 50Sequence analysisAdd BLAST50
<p>This subsection of the 'PTM / Processing' section describes the extent of a polypeptide chain in the mature protein following processing or proteolytic cleavage.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_000000566651 – ?Cell surface antigen I/II
ChainiPRO_0000005667? – 1506Cell surface antigen II
<p>This subsection of the <a href="http://www.uniprot.org/help/ptm%5Fprocessing%5Fsection">PTM / Processing</a> section describes a propeptide, which is a part of a protein that is cleaved during maturation or activation. Once cleaved, a propeptide generally has no independent biological function.<p><a href='/help/propep' target='_top'>More...</a></p>PropeptideiPRO_00000056681507 – 1528Removed by sortasePROSITE-ProRule annotationAdd BLAST22

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'PTM / Processing' section specifies the position and type of each modified residue excluding <a href="http://www.uniprot.org/manual/lipid">lipids</a>, <a href="http://www.uniprot.org/manual/carbohyd">glycans</a> and <a href="http://www.uniprot.org/manual/crosslnk">protein cross-links</a>.<p><a href='/help/mod_res' target='_top'>More...</a></p>Modified residuei1506Pentaglycyl murein peptidoglycan amidated threoninePROSITE-ProRule annotation1

Keywords - PTMi

Peptidoglycan-anchor

<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei

3D structure databases

SWISS-MODEL Repository - a database of annotated 3D protein structure models

More...
SMRi
P21979

Database of comparative protein structure models

More...
ModBasei
Search...

<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Family and Domains' section indicates the positions and types of repeated sequence motifs or repeated domains within the protein.<p><a href='/help/repeat' target='_top'>More...</a></p>Repeati161 – 235Ag I/II A 1PROSITE-ProRule annotationAdd BLAST75
Repeati236 – 315Ag I/II A 2PROSITE-ProRule annotationAdd BLAST80
Repeati316 – 396Ag I/II A 3PROSITE-ProRule annotationAdd BLAST81
Repeati397 – 478Ag I/II A 4PROSITE-ProRule annotationAdd BLAST82

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Family and Domains' section describes a region of interest that cannot be described in other subsections.<p><a href='/help/region' target='_top'>More...</a></p>Regioni50 – 156DisorderedSequence analysisAdd BLAST107
Regioni840 – 951DisorderedSequence analysisAdd BLAST112
Regioni1459 – 1480DisorderedSequence analysisAdd BLAST22

Motif

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Family and Domains' section describes a short (usually not more than 20 amino acids) conserved sequence motif of biological significance.<p><a href='/help/motif' target='_top'>More...</a></p>Motifi1503 – 1507LPXTG sorting signalPROSITE-ProRule annotation5

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Family and Domains' section describes the position of regions of compositional bias within the protein and the particular type of amino acids that are over-represented within those regions.<p><a href='/help/compbias' target='_top'>More...</a></p>Compositional biasi50 – 138Polar residuesSequence analysisAdd BLAST89
Compositional biasi139 – 156Basic and acidic residuesSequence analysisAdd BLAST18
Compositional biasi849 – 874Basic and acidic residuesSequence analysisAdd BLAST26
Compositional biasi876 – 890Pro residuesSequence analysisAdd BLAST15
Compositional biasi898 – 913Basic and acidic residuesSequence analysisAdd BLAST16
Compositional biasi915 – 929Pro residuesSequence analysisAdd BLAST15

<p>This subsection of the 'Family and domains' section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi

Belongs to the antigen I/II family.Curated

Keywords - Domaini

Repeat, Signal

Family and domain databases

Gene3D Structural and Functional Annotation of Protein Families

More...
Gene3Di
2.60.530.10, 1 hit

Integrated resource of protein families, domains and functional sites

More...
InterProi
View protein in InterPro
IPR026345, Adh_isopep-form_adh_dom
IPR041324, AgI/II_N
IPR032300, Antigen_C
IPR013574, Glucan-bd_C/Surface_Ag-I/II_V
IPR019931, LPXTG_anchor
IPR036234, SA_I/II_PAC_V_sf
IPR009578, Surface_Ag_rpt

Pfam protein domain database

More...
Pfami
View protein in Pfam
PF18652, Adhesin_P1_N, 1 hit
PF17998, AgI_II_C2, 1 hit
PF16364, Antigen_C, 1 hit
PF08363, GbpC, 1 hit
PF06696, Strep_SA_rep, 2 hits

Superfamily database of structural and functional annotation

More...
SUPFAMi
SSF74914, SSF74914, 1 hit

TIGRFAMs; a protein family database

More...
TIGRFAMsi
TIGR04228, isopep_sspB_C2, 1 hit

PROSITE; a protein domain and family database

More...
PROSITEi
View protein in PROSITE
PS51965, AG_I_II_AR, 4 hits
PS50847, GRAM_POS_ANCHORING, 1 hit

<p>This section displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including <a href="http://www.uniprot.org/help/sequence%5Flength">length</a> and <a href="http://www.uniprot.org/help/sequences">molecular weight</a>. The information is filed in different subsections. The current subsections and their content are listed below:<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequencei

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> displayed by default in the entry is complete or not.<p><a href='/help/sequence_status' target='_top'>More...</a></p>Sequence statusi: Complete.

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> displayed by default in the entry is in its mature form or if it represents the precursor.<p><a href='/help/sequence_processing' target='_top'>More...</a></p>Sequence processingi: The displayed sequence is further processed into a mature form.

P21979-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30         40         50
MLQKCKLEGI IICNEKRLLG AAKVKSGRTL SGALLGTAIL ASGAGQKALA
60 70 80 90 100
EETSTTSTSG GDTAVVGTET GNPATNLPDK QDNPSSQAET SQAQARQKTG
110 120 130 140 150
AMSVDVSTSE LDEAAKSPQE AGVTVSQDAT VNKGTVEPSD EANQKEPEIK
160 170 180 190 200
DDYSKQAADI QKATEDYKAS VAANQAETDR INQEIAAKKA QYEQDLAANK
210 220 230 240 250
AEVERSLMRM RKPRPIYEAK LAQNQKDLAA IQQANSDSQA AYAAAKEAYD
260 270 280 290 300
KEWARVQAAN AAAKKAYEEA LAANTAKNDQ IKAEIEAIQQ RSAKADYEAK
310 320 330 340 350
LAQYEKDLAA AQAGNAANEA DYQAKKAAYE QELARVQAAN AAAKQAYEQA
360 370 380 390 400
LAANSAKNAQ ITAENEAIQQ NAQAKADYEA KLAQYQKDLA AAQSGNAANE
410 420 430 440 450
ADYQEKLAAY EKELARVQAA NAAAKQAYEQ QVQQANAKNA EITEANRAIR
460 470 480 490 500
ERNAKAKTDY ELKLSKYQEE LAQYKKDLAE YPAKLQAYQD EQAAIKAALA
510 520 530 540 550
ELEKHKNEDG NLSEPSAQSL VYDLEPNAQV ALVTDGKLLK ASALDEAFSH
560 570 580 590 600
DEKNYNNHLL QPDNLNVTYL EQADDVASSV ELFGNFGDKA GWTTTVSNGA
610 620 630 640 650
EVKFASVLLK RGQSATATYT NLKNSYYNGK KISKVVYKYT VDPDSKFQNP
660 670 680 690 700
TGNVWLGIFT DPTLGVFASA YTGQNEKDTS IFIKNEFTFY DEDGNPIDFD
710 720 730 740 750
NALLSVASLN REHNSIEMAK DYSGTFVKIS GSSIGEKNGM IYATDTLNFK
760 770 780 790 800
KGEGGSLHTM YTRASEPGSG WDSADAPNSW YGAGAVRMSG PNNYITLGAT
810 820 830 840 850
SATNVLSLAE MPQVPGKDNT AGKKPNIWYS LNGKIRAVNV PKVTKEKPTP
860 870 880 890 900
PVEPTKPDEP TYEVEKELVD LPVEPKYEPE PTPPSKNPDQ SIPEKPVEPT
910 920 930 940 950
YEVEKELEPA PVEPSYEKEP TPPQSTPDQE EPEKPVEPSY QSLPTPPVEP
960 970 980 990 1000
VYETVPGPVS VPTVRYHYYK LAVQPGVTKE IKNQDDLDID KTLVAKQSTV
1010 1020 1030 1040 1050
KFQLKTADLP AGRPETTSFV LMDPLPSGYQ LNLEATKVAS PGFEASYDAM
1060 1070 1080 1090 1100
THTVTFTATA ETLAALNQDL TKAVATIYPT VVGQVLNDGA TYTNNFTLMV
1110 1120 1130 1140 1150
NDAYGIKSNI VRVTTPGKPN DPDNPSNNYI TPHKVNKNEN GVVIDGKSVL
1160 1170 1180 1190 1200
AGTTNYYELT WDLDQYKGDK SAKEIIQKGF FYVDDYPEEA LDLRTDLIKL
1210 1220 1230 1240 1250
TDANGKAVTG VSVADYASLE AAPAAVQDML KKANIIPKGA FQVFTADDPQ
1260 1270 1280 1290 1300
AFYDAYVVTG TDLTIVTPMT VKAEMGKTGG SYENRAYQID FGNGYESNLV
1310 1320 1330 1340 1350
VNNVPKINPE KDVTLTMDPA DSTNVDGQTI ALNQVFNYRL IGGIIPADHA
1360 1370 1380 1390 1400
EELFEYSFSD DYDQTGDQYT GQYKAFAKVD LTLKDGTIIK AGTDLTSYTE
1410 1420 1430 1440 1450
AQVDEANGQI VVTFKEDFLR SVSVDSAFQA EVYLQMKRIA VGTFANTYVN
1460 1470 1480 1490 1500
TVNGITYSSN TVRTSTPEPK QPSPVDPKTT TTVVFQPRQG KAYQPAPPAG
1510 1520
AQLPATGDSS NAYLPLLGLV SLTAGFSC
Length:1,528
Mass (Da):165,573
Last modified:February 1, 1996 - v2
<p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.</p> <p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.</p> <p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).</p> <p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x<sup>64</sup> + x<sup>4</sup> + x<sup>3</sup> + x + 1. The algorithm is described in the ISO 3309 standard. </p> <p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.<br /> <strong>Cyclic redundancy and other checksums</strong><br /> <a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:iB235F9CCD92838E0
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Sequence' section reports difference(s) between the canonical sequence (displayed by default in the entry) and the different sequence submissions merged in the entry. These various submissions may originate from different sequencing projects, different types of experiments, or different biological samples. Sequence conflicts are usually of unknown origin.<p><a href='/help/conflict' target='_top'>More...</a></p>Sequence conflicti427A → E in AAA26977 (PubMed:1694526).Curated1
Sequence conflicti431Q → K in AAA26977 (PubMed:1694526).Curated1
Sequence conflicti434Q → K in AAA26977 (PubMed:1694526).Curated1
Sequence conflicti531A → S in AAA26977 (PubMed:1694526).Curated1
Sequence conflicti600A → S in AAA26977 (PubMed:1694526).Curated1

Sequence databases

Select the link destinations:

EMBL nucleotide sequence database

More...
EMBLi

GenBank nucleotide sequence database

More...
GenBanki

DNA Data Bank of Japan; a nucleotide sequence database

More...
DDBJi
Links Updated
X57841 Genomic DNA Translation: CAA40973.1
M38210 Genomic DNA Translation: AAA26977.1

<p>This section provides links to proteins that are similar to the protein sequence(s) described in this entry at different levels of sequence identity thresholds (100%, 90% and 50%) based on their membership in UniProt Reference Clusters (<a href="http://www.uniprot.org/help/uniref">UniRef</a>).<p><a href='/help/similar_proteins_section' target='_top'>More...</a></p>Similar proteinsi

<p>This section is used to point to information related to entries and found in data collections other than UniProtKB.<p><a href='/help/cross_references_section' target='_top'>More...</a></p>Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X57841 Genomic DNA Translation: CAA40973.1
M38210 Genomic DNA Translation: AAA26977.1

3D structure databases

SMRiP21979
ModBaseiSearch...

Family and domain databases

Gene3Di2.60.530.10, 1 hit
InterProiView protein in InterPro
IPR026345, Adh_isopep-form_adh_dom
IPR041324, AgI/II_N
IPR032300, Antigen_C
IPR013574, Glucan-bd_C/Surface_Ag-I/II_V
IPR019931, LPXTG_anchor
IPR036234, SA_I/II_PAC_V_sf
IPR009578, Surface_Ag_rpt
PfamiView protein in Pfam
PF18652, Adhesin_P1_N, 1 hit
PF17998, AgI_II_C2, 1 hit
PF16364, Antigen_C, 1 hit
PF08363, GbpC, 1 hit
PF06696, Strep_SA_rep, 2 hits
SUPFAMiSSF74914, SSF74914, 1 hit
TIGRFAMsiTIGR04228, isopep_sspB_C2, 1 hit
PROSITEiView protein in PROSITE
PS51965, AG_I_II_AR, 4 hits
PS50847, GRAM_POS_ANCHORING, 1 hit

MobiDB: a database of protein disorder and mobility annotations

More...
MobiDBi
Search...

<p>This section provides general information on the entry.<p><a href='/help/entry_information_section' target='_top'>More...</a></p>Entry informationi

<p>This subsection of the 'Entry information' section provides a mnemonic identifier for a UniProtKB entry, but it is not a stable identifier. Each reviewed entry is assigned a unique entry name upon integration into UniProtKB/Swiss-Prot.<p><a href='/help/entry_name' target='_top'>More...</a></p>Entry nameiSPAA_STRDO
<p>This subsection of the 'Entry information' section provides one or more accession number(s). These are stable identifiers and should be used to cite UniProtKB entries. Upon integration into UniProtKB, each entry is assigned a unique accession number, which is called 'Primary (citable) accession number'.<p><a href='/help/accession_numbers' target='_top'>More...</a></p>AccessioniPrimary (citable) accession number: P21979
<p>This subsection of the 'Entry information' section shows the date of integration of the entry into UniProtKB, the date of the last sequence update and the date of the last annotation modification ('Last modified'). The version number for both the entry and the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: August 1, 1991
Last sequence update: February 1, 1996
Last modified: June 2, 2021
This is version 105 of the entry and version 2 of the sequence. See complete history.
<p>This subsection of the 'Entry information' section indicates whether the entry has been manually annotated and reviewed by UniProtKB curators or not, in other words, if the entry belongs to the Swiss-Prot section of UniProtKB (<strong>reviewed</strong>) or to the computer-annotated TrEMBL section (<strong>unreviewed</strong>).<p><a href='/help/entry_status' target='_top'>More...</a></p>Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

<p>This section contains any relevant information that doesn't fit in any other defined sections<p><a href='/help/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousi

Documents

  1. SIMILARITY comments
    Index of protein domains and families
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