ID   FIBER_BPK1E             Reviewed;         811 AA.
AC   P49714; Q2WC58;
DT   01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1996, sequence version 1.
DT   02-SEP-2026, entry version 108.
DE   RecName: Full=Tail spike protein {ECO:0000305};
DE            Short=TSP;
DE   AltName: Full=Endo-N-acetylneuraminidase;
DE            Short=Endo-N;
DE   AltName: Full=Endo-alpha-sialidase {ECO:0000303|PubMed:7626018};
DE            EC=3.2.1.129 {ECO:0000269|PubMed:11994155, ECO:0000269|PubMed:7626018};
DE   AltName: Full=EndoNE;
DE   Contains:
DE     RecName: Full=Mature tail spike protein {ECO:0000303|PubMed:11994155};
DE   Contains:
DE     RecName: Full=Intramolecular chaperone {ECO:0000303|PubMed:11994155};
GN   Name=GP90; Synonyms=END;
OS   Escherichia phage K1E (Bacteriophage K1E).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Autographivirales; Autosignataviridae; Molineuxvirinae; Vectrevirus.
OX   NCBI_TaxID=344022;
OH   NCBI_TaxID=562; Escherichia coli.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 1-6; 330-349 AND
RP   613-632, FUNCTION, AND CATALYTIC ACTIVITY.
RX   PubMed=7626018; DOI=10.1042/bj3090543;
RA   Long G.S., Bryant J.M., Taylor P.W., Luzio J.P.;
RT   "Complete nucleotide sequence of the gene encoding bacteriophage E
RT   endosialidase: implications for K1E endosialidase structure and function.";
RL   Biochem. J. 309:543-550(1995).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Gerardy-Schahn R., Hansen A., Brennecke T., Muehlenhoff M., Eckhardt M.,
RA   Ziesing S., Lottspeich F., Frosch M.;
RL   Submitted (SEP-1994) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   SEQUENCE REVISION TO 53-56; 523 AND 539.
RA   Muehlenhoff M.;
RL   Submitted (SEP-2005) to the EMBL/GenBank/DDBJ databases.
RN   [4]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=16689790; DOI=10.1111/j.1365-2958.2006.05173.x;
RA   Stummeyer K., Schwarzer D., Claus H., Vogel U., Gerardy-Schahn R.,
RA   Muhlenhoff M.;
RT   "Evolution of bacteriophages infecting encapsulated bacteria: lessons from
RT   Escherichia coli K1-specific phages.";
RL   Mol. Microbiol. 60:1123-1135(2006).
RN   [5]
RP   PROTEIN SEQUENCE OF 707-718, PROTEOLYTIC CLEAVAGE (MATURE TAIL SPIKE
RP   PROTEIN), MUTAGENESIS OF ASP-138 AND 706-SER-ASP-707, CATALYTIC ACTIVITY,
RP   BIOPHYSICOCHEMICAL PROPERTIES, AND FUNCTION (INTRAMOLECULAR CHAPERONE).
RX   PubMed=11994155; DOI=10.1046/j.1365-2958.2002.02908.x;
RA   Leggate D.R., Bryant J.M., Redpath M.B., Head D., Taylor P.W., Luzio J.P.;
RT   "Expression, mutagenesis and kinetic analysis of recombinant K1E
RT   endosialidase to define the site of proteolytic processing and requirements
RT   for catalysis.";
RL   Mol. Microbiol. 44:749-760(2002).
RN   [6]
RP   STRUCTURE BY ELECTRON MICROSCOPY (9.0 ANGSTROMS), SUBCELLULAR LOCATION
RP   (MATURE TAIL SPIKE PROTEIN), INTERACTION WITH ADAPTER PROTEIN GP37 (MATURE
RP   TAIL SPIKE PROTEIN), SUBUNIT (MATURE TAIL SPIKE PROTEIN), INTERACTION WITH
RP   GP46 (MATURE TAIL SPIKE PROTEIN), AND FUNCTION (MATURE TAIL SPIKE PROTEIN).
RX   PubMed=17585937; DOI=10.1016/j.jmb.2007.05.083;
RA   Leiman P.G., Battisti A.J., Bowman V.D., Stummeyer K., Muehlenhoff M.,
RA   Gerardy-Schahn R., Scholl D., Molineux I.J.;
RT   "The structures of bacteriophages K1E and K1-5 explain processive
RT   degradation of polysaccharide capsules and evolution of new host
RT   specificities.";
RL   J. Mol. Biol. 371:836-849(2007).
CC   -!- FUNCTION: [Mature tail spike protein]: Receptor binding protein, which
CC       mediates the attachment to the host capsule (PubMed:17585937,
CC       PubMed:7626018). Degrades the alpha-2,8-linked polysialic acid K1-type
CC       capsule by cleaving within the polymer chain of polysialic acid (By
CC       similarity). {ECO:0000250|UniProtKB:Q04830,
CC       ECO:0000269|PubMed:17585937, ECO:0000269|PubMed:7626018}.
CC   -!- FUNCTION: [Intramolecular chaperone]: The C-terminal chaperone protein
CC       mediates homotrimerization and proper folding of the catalytic
CC       endosialidase trimer. {ECO:0000269|PubMed:11994155}.
CC   -!- CATALYTIC ACTIVITY: [Mature tail spike protein]:
CC       Reaction=Endohydrolysis of (2->8)-alpha-sialosyl linkages in oligo- or
CC         poly(sialic) acids.; EC=3.2.1.129;
CC         Evidence={ECO:0000269|PubMed:11994155, ECO:0000269|PubMed:7626018};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES: [Mature tail spike protein]:
CC       Kinetic parameters:
CC         KM=17.7 uM for polysialic acid {ECO:0000269|PubMed:11994155};
CC   -!- SUBUNIT: [Mature tail spike protein]: Homotrimer (PubMed:17585937).
CC       Interacts with sialic acid (By similarity). Interacts with adapter
CC       protein gp37 (PubMed:17585937). Interacts with gp46 (PubMed:17585937).
CC       {ECO:0000250|UniProtKB:Q04830, ECO:0000269|PubMed:17585937}.
CC   -!- SUBCELLULAR LOCATION: [Mature tail spike protein]: Virion
CC       {ECO:0000269|PubMed:17585937}. Note=Tail spike.
CC       {ECO:0000269|PubMed:17585937}.
CC   -!- PTM: [Tail spike protein]: The N-terminus is blocked.
CC   -!- PTM: [Tail spike protein]: Proteolytic cleavage and release of the
CC       chaperone in the host cytosol stabilizes the folded protein
CC       (PubMed:11994155). The cleavage gives rise to the mature tail spike
CC       protein but is not essential for catalytic activity (PubMed:11994155).
CC       However, release of the chaperone domain confers kinetic stability and
CC       processivity to the endosialidase (By similarity).
CC       {ECO:0000250|UniProtKB:Q04830, ECO:0000269|PubMed:11994155}.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 58 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; X78310; CAA55120.1; -; Genomic_DNA.
DR   EMBL; Z36986; CAA85449.2; -; Genomic_DNA.
DR   EMBL; AM084415; CAJ29458.1; -; Genomic_DNA.
DR   RefSeq; YP_425027.1; NC_007637.1.
DR   AlphaFoldDB; P49714; -.
DR   SMR; P49714; -.
DR   CAZy; GH58; Glycoside Hydrolase Family 58.
DR   GeneID; 3837325; -.
DR   KEGG; vg:3837325; -.
DR   OrthoDB; 303at10239; -.
DR   BioCyc; MetaCyc:MONOMER-20295; -.
DR   Proteomes; UP000001154; Segment.
DR   GO; GO:0098024; C:virus tail, fiber; IEA:UniProtKB-KW.
DR   GO; GO:0016996; F:endo-alpha-(2,8)-sialidase activity; EXP:UniProtKB.
DR   GO; GO:0098671; P:adhesion receptor-mediated virion attachment to host cell; IEA:UniProtKB-KW.
DR   GO; GO:0098994; P:symbiont entry into host cell via disruption of host cell envelope; IEA:UniProtKB-KW.
DR   GO; GO:0098996; P:symbiont entry into host cell via disruption of host cell glycocalyx; IEA:UniProtKB-KW.
DR   CDD; cd10144; Peptidase_S74_CIMCD; 1.
DR   Gene3D; 2.120.10.10; -; 1.
DR   Gene3D; 2.40.30.20; -; 1.
DR   Gene3D; 4.10.1090.10; Endosialidase, domain 4; 1.
DR   Gene3D; 3.30.750.60; Endosialidase, N-terminal extension domain; 1.
DR   Gene3D; 1.10.10.10; Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain; 1.
DR   InterPro; IPR023366; ATP_synth_asu-like_sf.
DR   InterPro; IPR024427; B-barrel_Endosialidase.
DR   InterPro; IPR024428; Endosialidase_beta_prop.
DR   InterPro; IPR024430; Endosialidase_C_dom.
DR   InterPro; IPR044914; Endosialidase_C_dom_sf.
DR   InterPro; IPR024429; Endosialidase_N-extension.
DR   InterPro; IPR001724; Glycl_Hydrolase_58.
DR   InterPro; IPR030392; S74_ICA.
DR   InterPro; IPR036278; Sialidase_sf.
DR   InterPro; IPR036388; WH-like_DNA-bd_sf.
DR   Pfam; PF12195; End_beta_barrel; 1.
DR   Pfam; PF12217; End_beta_propel; 1.
DR   Pfam; PF12218; End_N_terminal; 1.
DR   Pfam; PF12219; End_tail_spike; 1.
DR   Pfam; PF13884; Peptidase_S74; 1.
DR   PRINTS; PR00849; GLHYDRLASE58.
DR   SUPFAM; SSF69349; Phage fibre proteins; 1.
DR   SUPFAM; SSF50939; Sialidases; 1.
DR   PROSITE; PS51688; ICA; 1.
PE   1: Evidence at protein level;
KW   Degradation of host capsule during virus entry;
KW   Degradation of host cell envelope components during virus entry;
KW   Direct protein sequencing; Glycosidase; Host-virus interaction; Hydrolase;
KW   Reference proteome; Repeat; Viral attachment to host adhesion receptor;
KW   Viral attachment to host cell; Viral tail fiber protein;
KW   Viral tail protein; Virion; Virus entry into host cell.
FT   CHAIN           1..811
FT                   /note="Tail spike protein"
FT                   /id="PRO_0000057708"
FT   CHAIN           1..706
FT                   /note="Mature tail spike protein"
FT                   /id="PRO_0000458687"
FT   CHAIN           707..811
FT                   /note="Intramolecular chaperone"
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT                   /id="PRO_0000438181"
FT   REPEAT          150..161
FT                   /note="BNR 1"
FT   REPEAT          286..293
FT                   /note="BNR 2"
FT   REPEAT          398..409
FT                   /note="BNR 3"
FT   DOMAIN          706..808
FT                   /note="Peptidase S74"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01025"
FT   ACT_SITE        371
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   ACT_SITE        386
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   ACT_SITE        437
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   SITE            332
FT                   /note="Binding to sialic acid"
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   SITE            335
FT                   /note="Binding to sialic acid"
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   SITE            339
FT                   /note="Binding to sialic acid"
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   SITE            368
FT                   /note="Binding to sialic acid"
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   SITE            388
FT                   /note="Binding to sialic acid"
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   SITE            389
FT                   /note="Binding to sialic acid"
FT                   /evidence="ECO:0000250|UniProtKB:Q04830"
FT   SITE            706..707
FT                   /note="Cleavage; by autolysis"
FT                   /evidence="ECO:0000269|PubMed:11994155"
FT   MUTAGEN         138
FT                   /note="D->A: Greatly reduced enzyme activity."
FT                   /evidence="ECO:0000269|PubMed:11994155"
FT   MUTAGEN         706..707
FT                   /note="SD->AA: Complete loss of enzymatic activity."
FT                   /evidence="ECO:0000269|PubMed:11994155"
FT   CONFLICT        640
FT                   /note="G -> R (in Ref. 4; CAJ29458)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        658
FT                   /note="N -> K (in Ref. 4; CAJ29458)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   811 AA;  90524 MW;  8F96F465ED533B6E CRC64;
     MIQRLGSSLV KFKSKIAGAI WRNLDDKLTE VVSLKDFGAK GDGKTNDQDA VNAAMASGKR
     IDGAGATYKV SSLPDMERFY NTRFVWERLA GQPLYYVSKG FINGELYKIT DNPYYNAWPQ
     DKAFVYENVI YAPYMGSDRH GVSRLHVSWV KSGDDGQTWS TPEWLTDMHP DYPTVNYHCM
     SMGVCRNRLF AMIETRTLAK NELTNCALWD RPMSRSLHLT GGITKAANQR YATIHVPDHG
     LFVGDFVNFS NSAVTGVSGD MKVATVIDKD NFTVLTPNQQ TSDLNNAGKN WHMGTSFHKS
     PWRKTDLGLI PRVTEVHSFA TIDNNGFVMG YHQGDVAPRE VGLFYFPDAF NSPSNYVRRQ
     IPSEYEPDAA EPCIKYYDGV LYLITRGTRG DRLGSSLHRS RDIGQTWESL RFPHNVHHTT
     LPFAKVGDDL IMFGSERAEN EWEAGAPDDR YKASYPRTFY ARLNVNNWNA DDIEWVNITD
     QIYQGDIVNS SVGVGSVVVK DSFIYYIFGG ENHFNPMTYG DNKDKDPFKG HGHPTDIYCY
     KMQIANDNRV SRKFTYGATP GQAIPTFMGT DGIRNIPAPL YFSDNIVTED TKVGHLTLKA
     STSANIRSEM QMEGEYGFIG KSVPKDKPTG QRLIICGGEG TSSSSGAQIT LHGSNSSNAK
     RITYNGNEHL FQGAPIMPAV DNQFAAGGPS NRFTTIYLGS DPVTTSDADH KYGISSINTK
     VLKAWSRVGF KQYGLNSEAE RNLDSIHFGV LAQDIVAAFE AEGLDAIKYG IVSFEEGRYG
     VRYSEVLILE AAYTRHRLDK LEEMYATNKI S
//