ID   BP45_BPMU               Reviewed;         197 AA.
AC   Q9T1V4;
DT   01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   08-NOV-2023, entry version 76.
DE   RecName: Full=Baseplate puncturing device gp45;
DE   AltName: Full=Baseplate spike protein;
DE   AltName: Full=Gene product 45;
DE            Short=gp45;
DE   AltName: Full=Gene product Q;
DE            Short=gpQ;
GN   OrderedLocusNames=Mup45;
OS   Escherichia phage Mu (Bacteriophage Mu).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Muvirus; Muvirus mu.
OX   NCBI_TaxID=2681603;
OH   NCBI_TaxID=543; Enterobacteriaceae.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=11922669; DOI=10.1006/jmbi.2002.5437;
RA   Morgan G.J., Hatfull G.F., Casjens S., Hendrix R.W.;
RT   "Bacteriophage Mu genome sequence: analysis and comparison with Mu-like
RT   prophages in Haemophilus, Neisseria and Deinococcus.";
RL   J. Mol. Biol. 317:337-359(2002).
RN   [2]
RP   DISRUPTION PHENOTYPE.
RX   PubMed=3904174; DOI=10.1016/0042-6822(85)90388-5;
RA   Grundy F.J., Howe M.M.;
RT   "Morphogenetic structures present in lysates of amber mutants of
RT   bacteriophage Mu.";
RL   Virology 143:485-504(1985).
RN   [3]
RP   INDUCTION.
RX   PubMed=8293968; DOI=10.1093/genetics/135.3.619;
RA   Chiang L.W., Howe M.M.;
RT   "Mutational analysis of a C-dependent late promoter of bacteriophage Mu.";
RL   Genetics 135:619-629(1993).
RN   [4]
RP   FUNCTION, AND SUBUNIT.
RX   PubMed=20478417; DOI=10.1016/j.bbapap.2010.05.003;
RA   Suzuki H., Yamada S., Toyama Y., Takeda S.;
RT   "The C-terminal domain is sufficient for host-binding activity of the Mu
RT   phage tail-spike protein.";
RL   Biochim. Biophys. Acta 1804:1738-1742(2010).
RN   [5]
RP   REVIEW.
RX   PubMed=22297511; DOI=10.1007/978-1-4614-0980-9_5;
RA   Leiman P.G., Shneider M.M.;
RT   "Contractile tail machines of bacteriophages.";
RL   Adv. Exp. Med. Biol. 726:93-114(2012).
RN   [6]
RP   SUBUNIT, AND SUBCELLULAR LOCATION.
RX   PubMed=27555589; DOI=10.1073/pnas.1607966113;
RA   Buettner C.R., Wu Y., Maxwell K.L., Davidson A.R.;
RT   "Baseplate assembly of phage Mu: Defining the conserved core components of
RT   contractile-tailed phages and related bacterial systems.";
RL   Proc. Natl. Acad. Sci. U.S.A. 113:10174-10179(2016).
RN   [7]
RP   X-RAY CRYSTALLOGRAPHY (1.44 ANGSTROMS) OF 92-197, FUNCTION, SUBUNIT,
RP   DOMAIN, COFACTOR, AND MUTAGENESIS OF ASP-188.
RX   PubMed=22922659; DOI=10.1016/j.bbapap.2012.08.015;
RA   Harada K., Yamashita E., Nakagawa A., Miyafusa T., Tsumoto K., Ueno T.,
RA   Toyama Y., Takeda S.;
RT   "Crystal structure of the C-terminal domain of Mu phage central spike and
RT   functions of bound calcium ion.";
RL   Biochim. Biophys. Acta 1834:284-291(2013).
CC   -!- FUNCTION: Component of the baseplate that forms a central needlelike
CC       spike used to puncture the host cell membrane for tube insertion during
CC       virus entry. Probably involved in baseplate and tail assembly. Serves
CC       as the distal plug of tail tube channel and might regulate the process
CC       of the phage DNA and protein ejection into the host cell.
CC       {ECO:0000269|PubMed:20478417, ECO:0000269|PubMed:22922659}.
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108;
CC         Evidence={ECO:0000269|PubMed:22922659};
CC       Note=Binds 1 Ca(2+) cation per trimer. Ca(2+) plays an important role
CC       in interaction with the host cell membrane.
CC       {ECO:0000269|PubMed:22922659};
CC   -!- COFACTOR:
CC       Name=chloride; Xref=ChEBI:CHEBI:17996;
CC         Evidence={ECO:0000269|PubMed:22922659};
CC       Note=Binds 1 Cl(-) ion per trimer. {ECO:0000269|PubMed:22922659};
CC   -!- COFACTOR:
CC       Name=Fe cation; Xref=ChEBI:CHEBI:24875;
CC         Evidence={ECO:0000269|PubMed:22922659};
CC       Note=Binds 1 Fe cation per trimer. {ECO:0000269|PubMed:22922659};
CC   -!- SUBUNIT: Homotrimer (PubMed:20478417, PubMed:22922659). Part of a
CC       complex composed of three DNA circularization protein N, three
CC       baseplate hub protein gp44 and three sub-complex wedge (made of two
CC       copies of each baseplate protein gp46, gp47 and gp48) that forms the
CC       baseplate (PubMed:27555589). {ECO:0000269|PubMed:20478417,
CC       ECO:0000269|PubMed:22922659, ECO:0000269|PubMed:27555589}.
CC   -!- SUBCELLULAR LOCATION: Virion {ECO:0000269|PubMed:27555589}. Host
CC       cytoplasm {ECO:0000305}. Note=Baseplate protein.
CC       {ECO:0000269|PubMed:27555589}.
CC   -!- INDUCTION: Expressed in the late phase of the viral replicative cycle.
CC       Expression of late genes is activated by the viral late transcription
CC       activator C. {ECO:0000269|PubMed:8293968}.
CC   -!- DOMAIN: The C-terminus is a needlelike shaped homotrimer consisting of
CC       an intertwined beta-sheet, a triple beta-helix and a metal-binding
CC       region. {ECO:0000269|PubMed:22922659}.
CC   -!- DISRUPTION PHENOTYPE: No tail is synthesized.
CC       {ECO:0000269|PubMed:3904174}.
CC   -!- CAUTION: Translation initiates from a non-canonical start codon (GUG).
CC       {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; AF083977; AAF01123.1; -; Genomic_DNA.
DR   RefSeq; NP_050649.1; NC_000929.1.
DR   PDB; 3VTN; X-ray; 1.75 A; A=100-197.
DR   PDB; 3VTO; X-ray; 1.44 A; A/B/C/P/Q/R=92-197.
DR   PDBsum; 3VTN; -.
DR   PDBsum; 3VTO; -.
DR   SMR; Q9T1V4; -.
DR   GeneID; 2636280; -.
DR   KEGG; vg:2636280; -.
DR   OrthoDB; 9898at10239; -.
DR   Proteomes; UP000002611; Genome.
DR   GO; GO:0030430; C:host cell cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0098025; C:virus tail, baseplate; IEA:UniProtKB-KW.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0099000; P:viral genome ejection through host cell envelope, contractile tail mechanism; IEA:UniProtKB-KW.
DR   GO; GO:0098003; P:viral tail assembly; IEA:UniProtKB-KW.
DR   Gene3D; 2.20.25.540; -; 1.
DR   Gene3D; 6.20.170.10; -; 1.
DR   InterPro; IPR013046; GpV/Gp45.
DR   InterPro; IPR014462; Phage_Mu_Gp45.
DR   InterPro; IPR040629; Phage_spike.
DR   NCBIfam; TIGR01644; phage_P2_V; 1.
DR   Pfam; PF06890; Phage_Mu_Gp45; 1.
DR   Pfam; PF18715; Phage_spike; 1.
DR   PIRSF; PIRSF012337; gp45; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Calcium; Chloride; Host cytoplasm; Iron; Late protein;
KW   Metal-binding; Reference proteome; Viral baseplate protein;
KW   Viral contractile tail ejection system;
KW   Viral genome ejection through host cell envelope;
KW   Viral penetration into host cytoplasm; Viral release from host cell;
KW   Viral tail assembly; Viral tail protein; Virion;
KW   Virus entry into host cell.
FT   CHAIN           1..197
FT                   /note="Baseplate puncturing device gp45"
FT                   /id="PRO_0000077838"
FT   REGION          172..197
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   BINDING         183
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_note="ligand shared between trimeric partners"
FT   BINDING         185
FT                   /ligand="Fe cation"
FT                   /ligand_id="ChEBI:CHEBI:24875"
FT                   /ligand_note="ligand shared between trimeric partners"
FT   BINDING         188
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_note="ligand shared between trimeric partners"
FT   BINDING         188
FT                   /ligand="chloride"
FT                   /ligand_id="ChEBI:CHEBI:17996"
FT                   /ligand_note="ligand shared between trimeric partners"
FT   BINDING         189
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_note="ligand shared between trimeric partners"
FT   MUTAGEN         188
FT                   /note="D->A: Loss of membrane-binding ability."
FT                   /evidence="ECO:0000269|PubMed:22922659"
FT   STRAND          104..107
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   STRAND          113..117
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   TURN            118..120
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   STRAND          121..140
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   STRAND          142..154
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   STRAND          156..160
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   STRAND          162..166
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   STRAND          168..171
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   STRAND          173..175
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   TURN            180..182
FT                   /evidence="ECO:0007829|PDB:3VTO"
FT   STRAND          190..192
FT                   /evidence="ECO:0007829|PDB:3VTO"
SQ   SEQUENCE   197 AA;  21689 MW;  448C7A7ADCADD5C9 CRC64;
     MERVNDSALN RLLTPLMRRV RLMLARAVVN VINDGRKVQN LQVGLLDDEE SDEVERLQNY
     GHFSVPLPGA EALIACVGAQ RDQGIAVVVE DRRYRPTNLE PGDAGIYHHE GHRIRLTKDG
     RCIITCKTVE VYADESMTVD TPRTTFTGDV EIQKGLGVKG KSQFDSNITA PDAIINGKST
     DKHIHRGDSG GTTGPMQ
//