ID   HOLIN_BPP2              Reviewed;          93 AA.
AC   P51773;
DT   01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1996, sequence version 1.
DT   25-MAY-2022, entry version 84.
DE   RecName: Full=Holin;
GN   Name=Y;
OS   Escherichia phage P2 (Bacteriophage P2).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Caudovirales; Myoviridae; Peduovirinae; Peduovirus.
OX   NCBI_TaxID=10679;
OH   NCBI_TaxID=543; Enterobacteriaceae.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=8051010; DOI=10.1128/jb.176.16.4974-4984.1994;
RA   Ziermann R., Bartlett B., Calendar R., Christie G.E.;
RT   "Functions involved in bacteriophage P2-induced host cell lysis and
RT   identification of a new tail gene.";
RL   J. Bacteriol. 176:4974-4984(1994).
RN   [2]
RP   FUNCTION, SUBUNIT, AND MUTAGENESIS OF GLY-50.
RX   PubMed=23335412; DOI=10.1128/jb.01986-12;
RA   To K.H., Dewey J., Weaver J., Park T., Young R.;
RT   "Functional analysis of a class I holin, P2 Y.";
RL   J. Bacteriol. 195:1346-1355(2013).
CC   -!- FUNCTION: Accumulates harmlessly in the cytoplasmic membrane until it
CC       reaches a critical concentration that triggers the formation of micron-
CC       scale pores (holes) causing host cell membrane disruption and endolysin
CC       escape into the periplasmic space (Probable). Determines the precise
CC       timing of host cell lysis (Probable). Participates with the endolysin
CC       and spanin proteins in the sequential events which lead to the
CC       programmed host cell lysis releasing the mature viral particles from
CC       the host cell (Probable). {ECO:0000305|PubMed:23335412}.
CC   -!- SUBUNIT: Homomultimer. Interacts with antiholin; this interaction
CC       blocks the holin homomultimerization and delays host cell lysis (By
CC       similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Host cell inner membrane
CC       {ECO:0000250|UniProtKB:P03705}; Multi-pass membrane protein
CC       {ECO:0000250|UniProtKB:P03705}. Note=Classified as a class I holin.
CC       {ECO:0000305|PubMed:23335412}.
CC   -!- DOMAIN: The C-terminus acts as a cytoplasmic regulatory region.
CC       {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the P2likevirus holin 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; AF063097; AAD03275.1; -; Genomic_DNA.
DR   PIR; C55855; C55855.
DR   RefSeq; NP_046764.1; NC_001895.1.
DR   TCDB; 1.E.3.1.1; the p2 holin (p2 holin) family.
DR   GeneID; 1261546; -.
DR   KEGG; vg:1261546; -.
DR   Proteomes; UP000009092; Genome.
DR   GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0034291; F:canonical holin activity; IDA:CACAO.
DR   GO; GO:0034290; F:holin activity; IDA:CACAO.
DR   GO; GO:0019835; P:cytolysis; IEA:UniProtKB-KW.
DR   InterPro; IPR007633; Phage_P2_Holin.
DR   Pfam; PF04550; Phage_holin_3_2; 1.
PE   1: Evidence at protein level;
KW   Cytolysis; Host cell inner membrane; Host cell lysis by virus;
KW   Host cell membrane; Host membrane; Membrane; Reference proteome;
KW   Transmembrane; Transmembrane helix; Viral release from host cell.
FT   CHAIN           1..93
FT                   /note="Holin"
FT                   /id="PRO_0000165241"
FT   TOPO_DOM        1..6
FT                   /note="Periplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        7..27
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        28..33
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        34..54
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        55..62
FT                   /note="Periplasmic"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        63..83
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        84..93
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   MUTAGEN         50
FT                   /note="G->V: Complete loss of lysis function, no effect on
FT                   accumulation."
FT                   /evidence="ECO:0000269|PubMed:23335412"
SQ   SEQUENCE   93 AA;  9818 MW;  F408A1261581F747 CRC64;
     MTAEEKSVLS LFMIGVLIVV GKVLAGGEPI TPRLFIGRML LGGFVSMVAG VVLVQFPDLS
     LPAVCGIGSM LGIAGYQVIE IAIQRRFKGR GKQ