ID   HOLIN_BPA18             Reviewed;          96 AA.
AC   Q37975;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   07-OCT-2020, entry version 81.
DE   RecName: Full=Putative antiholin;
GN   Name=hol; Synonyms=hol118;
OS   Listeria phage A118 (Bacteriophage A118).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Caudovirales; Siphoviridae.
OX   NCBI_TaxID=40521;
OH   NCBI_TaxID=1639; Listeria monocytogenes.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=8577256; DOI=10.1111/j.1365-2958.1995.tb02345.x;
RA   Loessner M.J., Wendlinger G., Scherer S.;
RT   "Heterogeneous endolysins in Listeria monocytogenes bacteriophages: a new
RT   class of enzymes and evidence for conserved holin genes within the
RT   siphoviral lysis cassettes.";
RL   Mol. Microbiol. 16:1231-1241(1995).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=10652093; DOI=10.1046/j.1365-2958.2000.01720.x;
RA   Loessner M.J., Inman R.B., Lauer P., Calendar R.;
RT   "Complete nucleotide sequence, molecular analysis and genome structure of
RT   bacteriophage A118 of Listeria monocytogenes: implications for phage
RT   evolution.";
RL   Mol. Microbiol. 35:324-340(2000).
CC   -!- FUNCTION: [Isoform Holin]: Accumulates harmlessly in the cytoplasmic
CC       membrane until it reaches a critical concentration that triggers the
CC       formation of micron-scale pores (holes) causing host cell membrane
CC       disruption and endolysin escape into the periplasmic space (By
CC       similarity). Determines the precise timing of host cell lysis (By
CC       similarity). Participates with the endolysin and spanin proteins in the
CC       sequential events which lead to the programmed host cell lysis
CC       releasing the mature viral particles from the host cell (By
CC       similarity). {ECO:0000250|UniProtKB:P03705}.
CC   -!- FUNCTION: Isoform Antiholin: Counteracts the aggregation of the holin
CC       molecules and thus of pore formation. {ECO:0000250|UniProtKB:P03705}.
CC   -!- SUBUNIT: [Isoform Holin]: Homomultimer. Interacts with isoform
CC       Antiholin; this interaction blocks the holin homomultimerization and
CC       delays host cell lysis. {ECO:0000250|UniProtKB:P03705}.
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}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative initiation; Named isoforms=2;
CC       Name=Putative antiholin;
CC         IsoId=Q37975-1; Sequence=Displayed;
CC       Name=Holin;
CC         IsoId=Q37975-2; Sequence=VSP_060169;
CC   -!- DOMAIN: Isoform Holin has 3 transmembrane regions whereas isoform
CC       Antiholin lacks the first transmembrane region.
CC       {ECO:0000250|UniProtKB:P03705}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=CAA59361.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; X85008; CAA59360.1; -; Genomic_DNA.
DR   EMBL; X85008; CAA59361.1; ALT_INIT; Genomic_DNA.
DR   EMBL; AJ242593; CAB53810.1; -; Genomic_DNA.
DR   PIR; S69798; S69798.
DR   RefSeq; NP_463485.1; NC_003216.1. [Q37975-1]
DR   TCDB; 1.E.21.2.1; the listeria phage a118 holin (hol118) family.
DR   GeneID; 922401; -.
DR   KEGG; vg:922401; -.
DR   Proteomes; UP000002666; 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:0019835; P:cytolysis; IEA:UniProtKB-KW.
DR   InterPro; IPR009708; Phage_A118_holin/antiholin.
DR   Pfam; PF06946; Phage_holin_5_1; 1.
PE   3: Inferred from homology;
KW   Alternative initiation; Cytolysis; Host cell inner membrane;
KW   Host cell lysis by virus; Host cell membrane; Host membrane; Membrane;
KW   Reference proteome; Transmembrane; Transmembrane helix;
KW   Viral release from host cell.
FT   CHAIN           1..96
FT                   /note="Putative antiholin"
FT                   /id="PRO_0000077798"
FT   TOPO_DOM        1..32
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P03705"
FT   TRANSMEM        33..55
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        56..60
FT                   /note="Periplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P03705"
FT   TRANSMEM        61..81
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        82..96
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P03705"
FT   VAR_SEQ         1..3
FT                   /note="Missing (in isoform Holin)"
FT                   /evidence="ECO:0000305"
FT                   /id="VSP_060169"
FT   TOPO_DOM        Q37975-2:1..4
FT                   /note="Periplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P03705"
FT   TRANSMEM        Q37975-2:5..25
FT                   /note="Helical"
FT                   /evidence="ECO:0000250|UniProtKB:P03705"
FT   TOPO_DOM        Q37975-2:26..29
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000250|UniProtKB:P03705"
SQ   SEQUENCE   96 AA;  10301 MW;  FBA716F7A3E8B49B CRC64;
     MIEMEFGKEL LVYMTFLVVV TPVFVQAIKK TELVPSKWLP TVSILIGAIL GALATFLDGS
     GSLATMIWAG ALAGAGGTGL FEQFTNRSKK YGEDDK