Non-enveloped, head-tail structure. The capsid is about 84-94 nm in diameter and has a T=16 icosahedral symmetry (Spounalikevirus) . The tail is 140-219 in length, contractile with globular structures at its tip, has 6 long terminal fibers, 6 short spikes and a double base plate.


Linear, dsDNA genome of 130-160 kb, encoding for about 190-230 proteins. Some Twortlikevirus might have circularly permuted genomes.


Genes are transcribed by operons.



  1. Adsorption: the phage attaches to the target cell through its tail fibers.
  2. Ejection of the viral DNA into host cell cytoplasm by contraction of the tail sheath.
  3. Transcription and translation of early genes.
  4. Replication of viral DNA. Transcription and translation of late genes.
  5. Assembly of an empty procapsid and packaging of the genome.
  6. Viral tail fibers assembly and viral tail assembly.
  7. Mature virions are released from the cell by lysis.

Matching UniProtKB/Swiss-Prot entries

51 entries grouped by strain (browse by keywords)

All proteins are shown (view only 16 complete proteome entries)

2 entries

Bacillus phage SP01 (Bacteriophage SP01) reference strain

PORTL_BPSP1 Probable portal protein
TSP_BPSP1 Tail sheath protein (TSP)

8 entries

Enterococcus phage phiEF24C (Enterococcus bacteriophage phi-EF24C) reference strain

PORTL_BPPHE Probable portal protein
VPN7_BPPHE Tail fiber protein
VPN6_BPPHE Virion protein 6
VPN4_BPPHE Virion protein 4
VPN1_BPPHE Putative tail sheath protein
VPN2_BPPHE Putative major capsid protein
VPN5_BPPHE Virion protein 5
BP40_BPPHE Virion protein 3 (Gene product 40) (gp40)

3 entries

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

PORTL_BPTWO Probable portal protein
GP168_BPTWO Gene product 168 (gp168)
TSP_BPTWO Tail sheath protein (TSP)

1 entry

Staphylococcus phage K reference strain

CAPSD_BPPGK Major capsid protein (Major head protein)

1 entry

Staphylococcus phage S25-3 reference strain

CAPSD_BPS25 Major capsid protein (Major head protein)

34 entries

Bacillus phage SP01 (Bacteriophage SP01)

YG29_BPSP1 Uncharacterized 16.2 kDa protein in gene 29 5'region
TF1_BPSP1 Transcription factor 1
DUHM_BPSP1 Deoxyuridylate hydroxymethyltransferase (Deoxyuridylate hydroxymethylase) (EC 2.1.2.-) (dUMP ...
RP28_BPSP1 RNA polymerase sigma GP28 factor
RP34_BPSP1 RNA polymerase sigma GP34 factor
GP27_BPSP1 Gene 27 protein
GP30_BPSP1 Gene 30 protein (GP30)
GP33_BPSP1 Gene 33 protein
GP42_BPSP1 Putative gene 42 protein
GP43_BPSP1 E22 protein (Gene 43 protein)
GP44_BPSP1 E3 protein (Gene 44 protein)
GP45_BPSP1 Putative gene 45 protein
GP46_BPSP1 Putative gene 46 protein
GP47_BPSP1 Putative gene 47 protein
GP48_BPSP1 Putative gene 48 protein
GP49_BPSP1 Putative gene 49 protein
GP50_BPSP1 Putative gene 50 protein
GP51_BPSP1 Putative gene 51 protein
GP52_BPSP1 Putative gene 52 protein
GP53_BPSP1 Putative gene 53 protein
GP54_BPSP1 Putative gene 54 protein
GP37_BPSP1 Putative gene 37 protein
GP38_BPSP1 Putative gene 38 protein
GP39_BPSP1 Putative gene 39 protein
GP40_BPSP1 Gene 40 protein
GP41_BPSP1 Putative gene 41 protein
GP55_BPSP1 Putative gene 55 protein
GP56_BPSP1 Putative gene 56 protein
GP57_BPSP1 Putative gene 57 protein
GP58_BPSP1 Putative gene 58 protein
GP59_BPSP1 Putative gene 59 protein
GP60_BPSP1 Putative gene 60 protein
DPOL_BPSP1 DNA polymerase (EC (EC 3.1.11.-)
HMUI_BPSP1 DNA endonuclease I-HmuI (EC 3.1.-.-) (HNH homing endonuclease I-HmuI)

1 entry

Listeria phage A511 (Bacteriophage A511)

ENLYS_BPA51 Endolysin (EC (Probable N-acetylmuramoyl-L-alanine amidase)

1 entry

Staphylococcus phage S25-4

CAPSD_BPS24 Major capsid protein (Major head protein)