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Entry version 142 (05 Jun 2019)
Sequence version 2 (01 Nov 1997)
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Protein

Xanthosine permease

Gene

xapB

Organism
Escherichia coli (strain K12)
Status
Reviewed-Annotation score:

Annotation score:5 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>
-Experimental evidence at protein leveli <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

Uptake of xanthosine. Driven by a proton motive force. Can also transport other nucleosides such as inosine, adenosine, cytidine, uridine and thymidine.1 Publication

<p>This subsection of the <a href="http://www.uniprot.org/help/function_section">Function</a> section describes regulatory mechanisms for enzymes, transporters or microbial transcription factors, and reports the components which regulate (by activation or inhibition) the reaction.<p><a href='/help/activity_regulation' target='_top'>More...</a></p>Activity regulationi

Transport is abolished by 2,4-dinitrophenol.1 Publication

<p>This subsection of the ‘Function’ section describes biophysical and chemical properties, such as maximal absorption, kinetic parameters, pH dependence, redox potentials and temperature dependence.<p><a href='/help/biophysicochemical_properties' target='_top'>More...</a></p>Kineticsi

  1. KM=136 µM for xanthosine1 Publication

    <p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:<p><a href='/help/gene_ontology' target='_top'>More...</a></p>GO - Molecular functioni

    GO - Biological processi

    <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>Keywordsi

    Biological processTransport

    Enzyme and pathway databases

    BioCyc Collection of Pathway/Genome Databases

    More...
    BioCyci
    EcoCyc:XAPB-MONOMER
    ECOL316407:JW2397-MONOMER
    MetaCyc:XAPB-MONOMER

    Protein family/group databases

    Transport Classification Database

    More...
    TCDBi
    2.A.1.10.2 the major facilitator superfamily (mfs)

    <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_and_taxonomy_section">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:
    Xanthosine permease1 Publication
    Alternative name(s):
    Xanthosine transporterCurated
    <p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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:xapB1 Publication
    Ordered Locus Names:b2406, JW2397
    <p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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>OrganismiEscherichia coli (strain K12)
    <p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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 identifieri83333 [NCBI]
    <p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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 lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacteralesEnterobacteriaceaeEscherichia
    <p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section is present for entries that are part of a <a href="http://www.uniprot.org/proteomes">proteome</a>, i.e. of a set of proteins thought to be expressed by organisms whose genomes have been completely sequenced.<p><a href='/help/proteomes_manual' target='_top'>More...</a></p>Proteomesi
    • UP000000318 <p>A UniProt <a href="http://www.uniprot.org/manual/proteomes_manual">proteome</a> can consist of several components. <br></br>The component name refers to the genomic component encoding a set of proteins.<p><a href='/help/proteome_component' target='_top'>More...</a></p> Componenti: Chromosome
    • UP000000625 Componenti: Chromosome

    Organism-specific databases

    Escherichia coli strain K12 genome database

    More...
    EcoGenei
    EG13159 xapB

    <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

    Topology

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    <p>This subsection of the <a href="http://www.uniprot.org/help/subcellular_location_section">'Subcellular location'</a> section describes the subcellular compartment where each non-membrane region of a membrane-spanning protein is found.<p><a href='/help/topo_dom' target='_top'>More...</a></p>Topological domaini1 – 9Cytoplasmic1 Publication9
    <p>This subsection of the <a href="http://www.uniprot.org/help/subcellular_location_section">'Subcellular location'</a> section describes the extent of a membrane-spanning region of the protein. It denotes the presence of both alpha-helical transmembrane regions and the membrane spanning regions of beta-barrel transmembrane proteins.<p><a href='/help/transmem' target='_top'>More...</a></p>Transmembranei10 – 30HelicalSequence analysisAdd BLAST21
    Topological domaini31 – 41Periplasmic1 PublicationAdd BLAST11
    Transmembranei42 – 62HelicalSequence analysisAdd BLAST21
    Topological domaini63 – 70Cytoplasmic1 Publication8
    Transmembranei71 – 91HelicalSequence analysisAdd BLAST21
    Transmembranei92 – 112HelicalSequence analysisAdd BLAST21
    Topological domaini113 – 136Cytoplasmic1 PublicationAdd BLAST24
    Transmembranei137 – 157HelicalSequence analysisAdd BLAST21
    Topological domaini158 – 159Periplasmic1 Publication2
    Transmembranei160 – 180HelicalSequence analysisAdd BLAST21
    Topological domaini181 – 209Cytoplasmic1 PublicationAdd BLAST29
    Transmembranei210 – 230HelicalSequence analysisAdd BLAST21
    Topological domaini231 – 254Periplasmic1 PublicationAdd BLAST24
    Transmembranei255 – 275HelicalSequence analysisAdd BLAST21
    Topological domaini276 – 277Cytoplasmic1 Publication2
    Transmembranei278 – 298HelicalSequence analysisAdd BLAST21
    Topological domaini299 – 306Periplasmic1 Publication8
    Transmembranei307 – 327HelicalSequence analysisAdd BLAST21
    Topological domaini328 – 348Cytoplasmic1 PublicationAdd BLAST21
    Transmembranei349 – 369HelicalSequence analysisAdd BLAST21
    Topological domaini370 – 381Periplasmic1 PublicationAdd BLAST12
    Transmembranei382 – 402HelicalSequence analysisAdd BLAST21
    Topological domaini403 – 418Cytoplasmic1 Publication1 PublicationAdd BLAST16

    GO - Cellular componenti

    Keywords - Cellular componenti

    Cell inner membrane, Cell membrane, Membrane

    <p>This section provides information on the disease(s) and phenotype(s) associated with a protein.<p><a href='/help/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechi

    <p>This subsection of the ‘Pathology and Biotech’ section describes the in vivo effects caused by ablation of the gene (or one or more transcripts) coding for the protein described in the entry. This includes gene knockout and knockdown, provided experiments have been performed in the context of a whole organism or a specific tissue, and not at the single-cell level.<p><a href='/help/disruption_phenotype' target='_top'>More...</a></p>Disruption phenotypei

    Mutant grows very slowly on xanthosine.1 Publication

    <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 describes the extent of a polypeptide chain in the mature protein following processing.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_00000660031 – 418Xanthosine permeaseAdd BLAST418

    Proteomic databases

    jPOST - Japan Proteome Standard Repository/Database

    More...
    jPOSTi
    P45562

    PaxDb, a database of protein abundance averages across all three domains of life

    More...
    PaxDbi
    P45562

    PRoteomics IDEntifications database

    More...
    PRIDEi
    P45562

    <p>This section provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.<p><a href='/help/interaction_section' target='_top'>More...</a></p>Interactioni

    Protein-protein interaction databases

    The Biological General Repository for Interaction Datasets (BioGrid)

    More...
    BioGridi
    4262006, 20 interactors

    STRING: functional protein association networks

    More...
    STRINGi
    511145.b2406

    <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

    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 amino acids that are over-represented within those regions.<p><a href='/help/compbias' target='_top'>More...</a></p>Compositional biasi310 – 313Poly-LeuSequence analysis4

    <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

    Keywords - Domaini

    Transmembrane, Transmembrane helix

    Phylogenomic databases

    evolutionary genealogy of genes: Non-supervised Orthologous Groups

    More...
    eggNOGi
    ENOG4105EAA Bacteria
    ENOG410ZVFU LUCA

    The HOGENOM Database of Homologous Genes from Fully Sequenced Organisms

    More...
    HOGENOMi
    HOG000026502

    InParanoid: Eukaryotic Ortholog Groups

    More...
    InParanoidi
    P45562

    KEGG Orthology (KO)

    More...
    KOi
    K11537

    Database for complete collections of gene phylogenies

    More...
    PhylomeDBi
    P45562

    Family and domain databases

    Integrated resource of protein families, domains and functional sites

    More...
    InterProi
    View protein in InterPro
    IPR020846 MFS_dom
    IPR036259 MFS_trans_sf
    IPR004740 Nuc_H_symport

    Pfam protein domain database

    More...
    Pfami
    View protein in Pfam
    PF03825 Nuc_H_symport, 1 hit

    Superfamily database of structural and functional annotation

    More...
    SUPFAMi
    SSF103473 SSF103473, 1 hit

    TIGRFAMs; a protein family database

    More...
    TIGRFAMsi
    TIGR00889 2A0110, 1 hit

    PROSITE; a protein domain and family database

    More...
    PROSITEi
    View protein in PROSITE
    PS50850 MFS, 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_length">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_section">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical_and_isoforms">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.

    P45562-1 [UniParc]FASTAAdd to basket
    « Hide
            10         20         30         40         50
    MSIAMRLKVM SFLQYFIWGS WLVTLGSYMI NTLHFTGANV GMVYSSKGIA
    60 70 80 90 100
    AIIMPGIMGI IADKWLRAER AYMLCHLVCA GVLFYAASVT DPDMMFWVML
    110 120 130 140 150
    VNAMAFMPTI ALSNSVSYSC LAQAGLDPVT AFPPIRVFGT VGFIVAMWAV
    160 170 180 190 200
    SLLHLELSSL QLYIASGASL LLSAYALTLP KIPVAEKKAT TSLASKLGLD
    210 220 230 240 250
    AFVLFKNPRM AIFFLFAMML GAVLQITNVF GNPFLHDFAR NPEFADSFVV
    260 270 280 290 300
    KYPSILLSVS QMAEVGFILT IPFFLKRFGI KTVMLMSMVA WTLRFGFFAY
    310 320 330 340 350
    GDPSTTGFIL LLLSMIVYGC AFDFFNISGS VFVEQEVDSS IRASAQGLFM
    360 370 380 390 400
    TMVNGVGAWV GSILSGMAVD YFSVDGVKDW QTIWLVFAGY ALFLAVIFFF
    410
    GFKYNHDPEK IKHRAVTH
    Length:418
    Mass (Da):46,140
    Last modified:November 1, 1997 - 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:iC056971AE8A719E8
    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 conflicti63 – 80DKWLR…HLVCA → VQMRARRTCIHAVSPGVC in CAA52048 (PubMed:7559336).CuratedAdd BLAST18
    Sequence conflicti293 – 299LRFGFFA → CALASSP in CAA52048 (PubMed:7559336).Curated7

    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
    X73828 Genomic DNA Translation: CAA52048.1
    U00096 Genomic DNA Translation: AAC75459.1
    AP009048 Genomic DNA Translation: BAA16274.1

    Protein sequence database of the Protein Information Resource

    More...
    PIRi
    E65014

    NCBI Reference Sequences

    More...
    RefSeqi
    NP_416901.1, NC_000913.3
    WP_000020402.1, NZ_LN832404.1

    Genome annotation databases

    Ensembl bacterial and archaeal genome annotation project

    More...
    EnsemblBacteriai
    AAC75459; AAC75459; b2406
    BAA16274; BAA16274; BAA16274

    Database of genes from NCBI RefSeq genomes

    More...
    GeneIDi
    946868

    KEGG: Kyoto Encyclopedia of Genes and Genomes

    More...
    KEGGi
    ecj:JW2397
    eco:b2406

    Pathosystems Resource Integration Center (PATRIC)

    More...
    PATRICi
    fig|1411691.4.peg.4326

    <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
    X73828 Genomic DNA Translation: CAA52048.1
    U00096 Genomic DNA Translation: AAC75459.1
    AP009048 Genomic DNA Translation: BAA16274.1
    PIRiE65014
    RefSeqiNP_416901.1, NC_000913.3
    WP_000020402.1, NZ_LN832404.1

    3D structure databases

    Database of comparative protein structure models

    More...
    ModBasei
    Search...

    SWISS-MODEL Interactive Workspace

    More...
    SWISS-MODEL-Workspacei
    Submit a new modelling project...

    Protein-protein interaction databases

    BioGridi4262006, 20 interactors
    STRINGi511145.b2406

    Protein family/group databases

    TCDBi2.A.1.10.2 the major facilitator superfamily (mfs)

    Proteomic databases

    jPOSTiP45562
    PaxDbiP45562
    PRIDEiP45562

    Protocols and materials databases

    Structural Biology KnowledgebaseSearch...

    Genome annotation databases

    EnsemblBacteriaiAAC75459; AAC75459; b2406
    BAA16274; BAA16274; BAA16274
    GeneIDi946868
    KEGGiecj:JW2397
    eco:b2406
    PATRICifig|1411691.4.peg.4326

    Organism-specific databases

    EchoBASE - an integrated post-genomic database for E. coli

    More...
    EchoBASEi
    EB2951
    EcoGeneiEG13159 xapB

    Phylogenomic databases

    eggNOGiENOG4105EAA Bacteria
    ENOG410ZVFU LUCA
    HOGENOMiHOG000026502
    InParanoidiP45562
    KOiK11537
    PhylomeDBiP45562

    Enzyme and pathway databases

    BioCyciEcoCyc:XAPB-MONOMER
    ECOL316407:JW2397-MONOMER
    MetaCyc:XAPB-MONOMER

    Miscellaneous databases

    Protein Ontology

    More...
    PROi
    PR:P45562

    Family and domain databases

    InterProiView protein in InterPro
    IPR020846 MFS_dom
    IPR036259 MFS_trans_sf
    IPR004740 Nuc_H_symport
    PfamiView protein in Pfam
    PF03825 Nuc_H_symport, 1 hit
    SUPFAMiSSF103473 SSF103473, 1 hit
    TIGRFAMsiTIGR00889 2A0110, 1 hit
    PROSITEiView protein in PROSITE
    PS50850 MFS, 1 hit

    ProtoNet; Automatic hierarchical classification of proteins

    More...
    ProtoNeti
    Search...

    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 nameiXAPB_ECOLI
    <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: P45562
    Secondary accession number(s): P77729
    <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_and_isoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: November 1, 1995
    Last sequence update: November 1, 1997
    Last modified: June 5, 2019
    This is version 142 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

    Keywords - Technical termi

    Complete proteome, Reference proteome

    Documents

    1. SIMILARITY comments
      Index of protein domains and families
    2. Escherichia coli
      Escherichia coli (strain K12): entries and cross-references to EcoGene
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