Viral contractile tail ejection system

The long and contractile tail of Myoviridae acts as a molecular machine that ejects the viral DNA from the capsid into the host cell cytoplasm. The ejection system consists of a baseplate, a central tube and an external contractile sheath .

Upon binding to the host cell surface, the baseplate changes its conformation and triggers sheath contraction, driving the rigid internal tail tube through the cell envelope.

The source of the forces that drive viral genome ejection is probably in part due to osmotic pressure imbalance between the virus inside and the host cytoplasm .

Gram(-) hosts:

  1. Attachment to a host cell outer membrane (OM) receptor.
  2. Tail sheath contraction. Ejection of the internal rigid tube through the OM using the puncturing device.
  3. Virion-associated exolysin (if present) hydrolyzes the peptidoglycan layer. Ejection of the internal rigid tube through the cell wall.
  4. Complete contraction and ejection of the internal rigid tube. Fusion with the inner membrane.
  5. Viral DNA translocation into host cytoplasm.

Gram(+) hosts:

  1. Attachment to a host cell wall receptor.
  2. Tail sheath contraction. Virion-associated exolysin (if present) hydrolyzes the peptidoglycan layer. Ejection of the internal rigid tube through the cell wall.
  3. Complete contraction and ejection of the internal rigid tube. Possible ejection of the tape-measure protein and opening of the proximal plug. Fusion with the plasma membrane.
  4. Viral DNA translocation into host cytoplasm.

Matching UniProtKB/Swiss-Prot entries

30 entries grouped by protein (browse by keywords)

All proteins are shown (view only 26 complete proteome entries)

1 entry

Baseplate hub protein gp44 (43 kDa tail protein) (Gene product 44) (gp44) (Gene product P) (gpP)

BP44_BPMU
Escherichia phage Mu (Bacteriophage Mu) reference strain

1 entry

Baseplate puncturing device gp45 (Baseplate spike protein) (Gene product 45) (gp45) (Gene product Q) (gpQ)

BP45_BPMU
Escherichia phage Mu (Bacteriophage Mu) reference strain

11 entries

Probable portal protein

Select_allDeselect_all
PORTL_BPHA1
Halomonas phage phiHAP-1 (isolate -/Gulf of Mexico/-/2001) (Bacteriophage phiHAP-1) reference strain
PORTL_BPHC1
Haemophilus phage HP1 (strain HP1c1) (Bacteriophage HP1) reference strain

Probable portal protein (ORF15)

PORTL_BPKVM
Vibrio phage KVP40 (isolate Vibrio parahaemolyticus/Japan/Matsuzaki/1991) (KVP40) (Bacteriophage KVP40) reference strain

Portal protein

PORTL_BPMU
Escherichia phage Mu (Bacteriophage Mu) reference strain

Portal protein (Gene product 29) (gp29) (Gene product H) (gpH) (Head-tail connector)

PORTL_BPP2
Escherichia phage P2 (Bacteriophage P2) reference strain

Probable portal protein (GpQ)

PORTL_BPPCD
Clostridium phage phiCD119 (strain Clostridium difficile/United States/Govind/2006) (Bacteriophage phiCD119) reference strain

Portal protein (Portal vertex protein)

PORTL_BPPHE
Enterococcus phage phiEF24C (Enterococcus bacteriophage phi-EF24C) reference strain
PORTL_BPSAV
Salmonella phage ViI reference strain

Portal protein

PORTL_BPSP1
Bacillus phage SP01 (Bacteriophage SP01) reference strain
PORTL_BPT4
Enterobacteria phage T4 (Bacteriophage T4) reference strain

Portal protein gp20 (Gene product 20) (gp20)

PORTL_BPTWO
Staphylococcus phage Twort (strain DSM 17442) (Bacteriophage Twort) reference strain

1 entry

Major tail tube protein (GpFII-like protein) (Virion protein C)

TAILC_BPSK2
Serratia phage KSP20 (Serratia marcescens bacteriophage KSP20)

11 entries

Tail sheath protein (TSP)

Select_allDeselect_all
TSP_BPBMU
Burkholderia phage BcepMu (isolate -/United States/Summer/2002) (Bacteriophage BcepMu) reference strain
TSP_BPKVM
Vibrio phage KVP40 (isolate Vibrio parahaemolyticus/Japan/Matsuzaki/1991) (KVP40) (Bacteriophage KVP40) reference strain
TSP_BPMBZ
Mycobacterium phage Bxz1 (Mycobacteriophage Bxz1) reference strain

Tail sheath protein (TSP) (Gene product 124) (gp124)

TSP_BPMU
Escherichia phage Mu (Bacteriophage Mu) reference strain

Tail sheath protein (TSP) (Gene product 39) (gp39) (Gene product L) (gpL)

TSP_BPP2
Escherichia phage P2 (Bacteriophage P2) reference strain

Tail sheath protein (TSP) (Major tail sheath protein) (Protein FI)

TSP_BPPCD
Clostridium phage phiCD119 (strain Clostridium difficile/United States/Govind/2006) (Bacteriophage phiCD119) reference strain
TSP_BPSAV
Salmonella phage ViI reference strain
TSP_BPSP1
Bacillus phage SP01 (Bacteriophage SP01) reference strain
TSP_BPT4
Enterobacteria phage T4 (Bacteriophage T4) reference strain

Tail sheath protein (TSP) (Gene product 18) (gp18)

TSP_BPTWO
Staphylococcus phage Twort (strain DSM 17442) (Bacteriophage Twort) reference strain
TSP_BPSK2
Serratia phage KSP20 (Serratia marcescens bacteriophage KSP20)

Major tail sheath protein (Virion protein A)

5 entries

Tail tube protein gp19 (Gene product 19) (gp19)

Select_allDeselect_all
TUBE_BPMU
Escherichia phage Mu (Bacteriophage Mu) reference strain

Tail tube protein (TTP) (Gene product 40) (gp40) (Gene product M) (gpM)

TUBE_BPP2
Escherichia phage P2 (Bacteriophage P2) reference strain

Tail tube protein (TTP) (Protein FII)

TUBE_BPT4
Enterobacteria phage T4 (Bacteriophage T4) reference strain
TUBE_BPSK9
Serratia phage KSP90 (Serratia marcescens bacteriophage KSP90)

Tail tube protein (Virion protein F)

TUBE_BPT6
Enterobacteria phage T6 (Bacteriophage T6)