ID   HN_PI2H                 Reviewed;         571 AA.
AC   P25465;
DT   01-MAY-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1992, sequence version 1.
DT   02-SEP-2026, entry version 110.
DE   RecName: Full=Hemagglutinin-neuraminidase;
DE            EC=3.2.1.18 {ECO:0000269|PubMed:39318127};
GN   Name=HN;
OS   Human parainfluenza 2 virus (HPIV-2).
OC   Viruses; Riboviria; Orthornavirae; Negarnaviricota; Haploviricotina;
OC   Monjiviricetes; Mononegavirales; Paramyxoviridae; Rubulavirinae;
OC   Orthorubulavirus; Orthorubulavirus laryngotracheitidis.
OX   NCBI_TaxID=2560525;
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=2161050; DOI=10.1099/0022-1317-71-5-1163;
RA   Precious B., Southern J.A., Randall R.E.;
RT   "Sequence analysis of the HN gene of parainfluenza virus type 2.";
RL   J. Gen. Virol. 71:1163-1168(1990).
RN   [2]
RP   CATALYTIC ACTIVITY.
RC   STRAIN=Isolate human/Japan/456/2019;
RX   PubMed=39318127; DOI=10.1111/1348-0421.13170;
RA   Yang J., Kisu T., Watanabe O., Kitai Y., Ohmiya S., Fan Y., Nishimura H.;
RT   "Analysis of neuraminidase activity of human parainfluenza viruses using
RT   enzyme-linked lectin assay and BTP3-Neu5Ac assay.";
RL   Microbiol. Immunol. 68:371-380(2024).
CC   -!- FUNCTION: Attaches the virus to sialic acid-containing cell receptors
CC       and thereby initiating infection. Binding of HN protein to the receptor
CC       induces a conformational change that allows the F protein to trigger
CC       virion/cell membranes fusion (By similarity). {ECO:0000250}.
CC   -!- FUNCTION: Neuraminidase activity ensures the efficient spread of the
CC       virus by dissociating the mature virions from the neuraminic acid
CC       containing glycoproteins. {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of alpha-(2->3)-, alpha-(2->6)-, alpha-
CC         (2->8)- glycosidic linkages of terminal sialic acid residues in
CC         oligosaccharides, glycoproteins, glycolipids, colominic acid and
CC         synthetic substrates.; EC=3.2.1.18;
CC         Evidence={ECO:0000269|PubMed:39318127};
CC   -!- SUBUNIT: Homotetramer; composed of disulfide-linked homodimers (By
CC       similarity). Interacts with F protein trimer (By similarity).
CC       {ECO:0000250|UniProtKB:P04853, ECO:0000250|UniProtKB:Q9WAF5}.
CC   -!- SUBCELLULAR LOCATION: Virion membrane {ECO:0000305}; Single-pass type
CC       II membrane protein {ECO:0000305}. Host cell membrane {ECO:0000305};
CC       Single-pass type II membrane protein {ECO:0000305}.
CC   -!- DOMAIN: The C-terminus (head domain) is involved in binding the
CC       cellular receptor. {ECO:0000250|UniProtKB:Q9WAF5}.
CC   -!- SIMILARITY: Belongs to the paramyxoviruses hemagglutinin-neuraminidase
CC       family. {ECO:0000305}.
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DR   EMBL; D00865; BAA00739.1; -; mRNA.
DR   PIR; A34767; HNNZT2.
DR   AlphaFoldDB; P25465; -.
DR   SMR; P25465; -.
DR   GlyCosmos; P25465; 9 sites, No reported glycans.
DR   GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0019031; C:viral envelope; IEA:UniProtKB-KW.
DR   GO; GO:0055036; C:virion membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0004308; F:exo-alpha-sialidase activity; EXP:UniProtKB.
DR   GO; GO:0046789; F:host cell surface receptor binding; IEA:InterPro.
DR   GO; GO:0046718; P:symbiont entry into host cell; IEA:UniProtKB-KW.
DR   GO; GO:0019062; P:virion attachment to host cell; IEA:UniProtKB-KW.
DR   CDD; cd15469; HN; 1.
DR   Gene3D; 1.20.5.110; -; 1.
DR   Gene3D; 2.120.10.10; -; 1.
DR   InterPro; IPR016285; Hemagglutn-neuramid.
DR   InterPro; IPR000665; Hemagglutn/HN.
DR   InterPro; IPR036278; Sialidase_sf.
DR   Pfam; PF00423; HN; 1.
DR   PIRSF; PIRSF001072; Hemagglut-neuramid_paramyxoV; 1.
DR   SUPFAM; SSF50939; Sialidases; 1.
PE   1: Evidence at protein level;
KW   Disulfide bond; Glycoprotein; Hemagglutinin; Host cell membrane;
KW   Host membrane; Host-virus interaction; Hydrolase; Membrane; Signal-anchor;
KW   Transmembrane; Transmembrane helix; Viral attachment to host cell;
KW   Viral envelope protein; Virion; Virus entry into host cell.
FT   CHAIN           1..571
FT                   /note="Hemagglutinin-neuraminidase"
FT                   /id="PRO_0000142622"
FT   TOPO_DOM        1..25
FT                   /note="Intravirion"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        26..46
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        47..571
FT                   /note="Virion surface"
FT                   /evidence="ECO:0000255"
FT   REGION          228..233
FT                   /note="Involved in neuraminidase activity"
FT                   /evidence="ECO:0000250|UniProtKB:Q91UL0"
FT   CARBOHYD        272
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        284
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        335
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        386
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        454
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        498
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        501
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        517
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        522
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   DISULFID        166..190
FT                   /evidence="ECO:0000250|UniProtKB:Q9WAF5"
FT   DISULFID        180..241
FT                   /evidence="ECO:0000250|UniProtKB:Q9WAF5"
FT   DISULFID        232..245
FT                   /evidence="ECO:0000250|UniProtKB:Q9WAF5"
FT   DISULFID        338..459
FT                   /evidence="ECO:0000250|UniProtKB:Q9WAF5"
FT   DISULFID        370..380
FT                   /evidence="ECO:0000250|UniProtKB:Q9WAF5"
FT   DISULFID        453..463
FT                   /evidence="ECO:0000250|UniProtKB:Q9WAF5"
FT   DISULFID        535..546
FT                   /evidence="ECO:0000250|UniProtKB:Q9WAF5"
SQ   SEQUENCE   571 AA;  63316 MW;  56B4DCFA4337F392 CRC64;
     MEDYSNLSLK SIPKRTCRII FRTATILGIC TLIVLCSSIL HEIIHLDVSS GLMDSDDSQQ
     GIIQPIIESL KSLIALANQI LYNVAIIIPL KIDSIETVIY SALKDMHTGS MSNTNCTPGN
     LLLHDAAYIN GLNKFLVLKS YNGTPKYGPL LNIPSFIPSA TSPNGCTRIP SFSLIKTHWC
     YTHNVILGDC LDFTTSNQYL AMGIIQQSAA AFPIFRTMKT IYLSDGINRK SCSVTAIPGG
     CVLYCYVATR SEKEDYATTD LAELRLAFYY YNDTFIERVI SLPNTTGQWA TINPAVGSGI
     YHLGFILFPV YGGLIKGTPS YNKQSSRYFI PKHPNITCAG KSSEQAAAAR SSYVIRYHSN
     RLLQSAVLIC PLSDMHTARC NLVMFNNSQV MMGAEGRLYV IDNNLYYYQR SSSWWSASLF
     YRINTDFSKG IPPIIEAQWV PSYQVPRPGV MPCNATSFCP ANCITGVYAD VWPLNDPEPT
     SQNALNPNYR FAGAFLRNES NRTNPTFYTA SASALLNTTG FNNTNHKAAY TSSTCFKNTG
     TQKIYCLIII EMGSSLLGEF QIIPFLRELI P
//