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

36 entries grouped by strain (browse by keywords)

36 entries

Bacillus phage SP01 (Bacteriophage SP01) reference strain

PORTL_BPSP1 Probable portal protein
TSP_BPSP1 Tail sheath protein (TSP)
TF1_BPSP1 Transcription factor 1
GP42_BPSP1 Putative gene 42 protein
RP34_BPSP1 RNA polymerase sigma GP34 factor
RP28_BPSP1 RNA polymerase sigma GP28 factor
YG29_BPSP1 Uncharacterized 16.2 kDa protein in gene 29 5'region
GP56_BPSP1 Putative gene 56 protein
DUHM_BPSP1 Deoxyuridylate hydroxymethyltransferase (Deoxyuridylate hydroxymethylase) (EC 2.1.2.-) (dUMP ...
DPOL_BPSP1 DNA polymerase (EC (EC 3.1.11.-)
GP43_BPSP1 E22 protein (Gene 43 protein)
GP41_BPSP1 Putative gene 41 protein
GP45_BPSP1 Putative gene 45 protein
GP58_BPSP1 Putative gene 58 protein
GP59_BPSP1 Putative gene 59 protein
GP37_BPSP1 Putative gene 37 protein
GP51_BPSP1 Putative gene 51 protein
GP49_BPSP1 Putative gene 49 protein
GP46_BPSP1 Putative gene 46 protein
GP33_BPSP1 Gene 33 protein
GP39_BPSP1 Putative gene 39 protein
GP55_BPSP1 Putative gene 55 protein
GP47_BPSP1 Putative gene 47 protein
GP44_BPSP1 E3 protein (Gene 44 protein)
HMUI_BPSP1 DNA endonuclease I-HmuI (EC 3.1.-.-) (HNH homing endonuclease I-HmuI)
GP27_BPSP1 Gene 27 protein
GP30_BPSP1 Gene 30 protein (GP30)
GP48_BPSP1 Putative gene 48 protein
GP50_BPSP1 Putative gene 50 protein
GP52_BPSP1 Putative gene 52 protein
GP54_BPSP1 Putative gene 54 protein
GP40_BPSP1 Gene 40 protein
GP38_BPSP1 Putative gene 38 protein
GP53_BPSP1 Putative gene 53 protein
GP57_BPSP1 Putative gene 57 protein
GP60_BPSP1 Putative gene 60 protein