Non-enveloped, head-tail structure. The icosahedral head is about 54 nm with a knob-like neck. The tails is contractile, has a baseplate and 6 short fibers.


Linear, dsDNA genome of about 40 kb, encoding for 56 proteins. 50-150 bp and about 2 Kb of bacterial DNA are respectively covalently linked at the left and the right end of Mu genome. The presence of these pieces of bacterial DNA is due to the headful packaging mechanism.


Genes are transcribed by operons.



  1. Adsorption: the phage attaches to the target cell lipopolysaccharides (LPS) through its tail fibers. Two types of fibers are encoded by the phage to allow receptor tropism switching.
  2. Ejection of the viral DNA into host cell cytoplasm by contraction of the tail sheath.
  3. Viral DNA ends are protected from degradation by host nucleases.
  4. ?Transcription and translation of early genes?
  5. Circularization and supercoiling of the viral DNA.
  6. Integration of viral DNA into the host chromosome.
  7. Replicative transposition gives rise to 50-100 new copies of the viral genome in the host chromosome.
  8. Transcription and translation of late genes.
  9. Assembly of an empty procapsid.
  10. Momylation of viral DNA (modification of adenines) makes the packaged viral DNA resistant to host restriction enzymes.
  11. Viral tail fibers assembly and viral tail assembly.
  12. Mature virions are released from the cell by lysis.

Matching UniProtKB/Swiss-Prot entries

64 entries grouped by strain (browse by keywords)

55 entries

Escherichia phage Mu (Bacteriophage Mu) reference strain

ENLYS_BPMU Endolysin (EC (Gene product 22) (gp22) (Lysis protein) (Lysozyme) (Muramidase)
GP38_BPMU Putative sheath terminator protein (Gene product 38) (gp38)
MOR_BPMU Middle operon regulator (Mor) (GemB) (Gene product 17) (gp17)
KIL_BPMU Protein kil (Gene product 5) (gp5) (Protein cim)
MOM_BPMU Adenine modification enzyme mom (Adenine acetyltransferase) (EC 2.3.1.-) (Gene product 55) (gp55) ...
NER_BPMU Negative regulator of transcription (Ner) (Gene product 2) (gp2)
GP14_BPMU Uncharacterized protein gp14 (E15) (Gene product 14) (gp14)
GP6_BPMU Uncharacterized protein gp6 (E5) (Gene product 6) (gp6)
GP13_BPMU Uncharacterized protein gp13 (E14) (Gene product 13) (gp13)
GP24_BPMU Uncharacterized protein gp24 (Gene product 24) (gp24)
GP15_BPMU Uncharacterized protein gp15 (Gene product 15) (gp15)
GPF_BPMU Putative capsid assembly protein F (Gene product 30) (gp30) (Gene product F) (gpF)
GP12_BPMU Uncharacterized protein gp12 (E13) (Gene product 12) (gp12)
GP11_BPMU Uncharacterized protein gp11 (Gene product 11) (gp11)
GP8_BPMU Uncharacterized protein gp8 (E7) (Gene product 8) (gp8)
GP9_BPMU Uncharacterized protein gp9 (E8) (Gene product 9) (gp9)
GP18_BPMU Uncharacterized protein gp18 (E18) (E18 protein) (Gene product 18)
GPG_BPMU Putative capsid assembly protein G (Gene product G) (gpG)
GPJ_BPMU Gene product J (gpJ) (Gene product 36) (gp36)
GP26_BPMU Uncharacterized protein gp26 (Gene product 26) (gp26)
GP7_BPMU Uncharacterized protein gp7 (E6) (Gene product 7) (gp7)
GEMA_BPMU GemA protein (Gene product 16) (gp16)
GIN_BPMU Serine recombinase gin (EC 3.1.22.-) (EC 6.5.1.-) (G-segment invertase) (Gin) (Gene product 53) ...
GP19_BPMU Uncharacterized protein gp19 (E19 protein) (Gene product 19) (gp19)
GP25_BPMU Uncharacterized protein gp25 (Gene product 25) (gp25)
GP35_BPMU Uncharacterized protein gp35 (Gene product 35) (gp35)
ACTC_BPMU Late transcription activator C (C) (Gene product 21) (gp21) (Protein C)
PORTL_BPMU Portal protein (Gene product 29) (gp29) (Gene product H) (gpH) (Head-tail connector)
PRO_BPMU Protease I (Gene product 32) (gp32) (Gene product I) (gpI)
REPC_BPMU Repressor protein c (Repc) (CI) (Gene product 1) (gp1) (Mu repressor) (MuR)
TSP_BPMU Tail sheath protein (TSP) (Gene product 39) (gp39) (Gene product L) (gpL)
GAM_BPMU Putative DNA ends protecting protein gam (Gene product 10) (gp10)
TERS_BPMU Probable terminase, small subunit gp27 (Gene product 27) (gp27) (Gene product D) (gpD) (Pacase, ...
TERL_BPMU Probable terminase, large subunit gp28 (EC 3.1.-.-) (Gene product 28) (gp28) (Gene product E) (gpE) ...
S1_BPMU Tail fiber protein S (Gene product 49) (gp49) (Gene product S) (gpS)
S2_BPMU Tail fiber protein S' (Gene product S') (gpS')
TAP_BPMU Probable tail assembly protein gp41 (Gene product 41) (gp41) (Tail assembly chaperone)
TARGB_BPMU ATP-dependent target DNA activator B (EC (Gene product 04) (gp04) (Gene product B) (gpB) ...
SPAN1_BPMU Probable spanin, inner membrane subunit (i-spanin) (gene product 23) (gp23)
TMP_BPMU Probable tape measure protein (TMP) (Gene product 42) (gp42) (Gene product Y) (gpY)
TNPA_BPMU DDE-recombinase A (EC 3.1.22.-) (EC 6.5.1.-) (DDE-transposase A) (Gene product 03) (gp03) (Gene ...
TRP_BPMU Probable tail terminator protein (TrP) (Gene product 37) (gp37) (Gene product K) (gpK)
TAPFS_BPMU Probable tail assembly protein FS-gp41
TUBE_BPMU Tail tube protein (TTP) (Gene product 40) (gp40) (Gene product M) (gpM)
COM_BPMU Translational activator com (Gene product 54) (gp54) (Gene product com) (gpCom)
CIRCN_BPMU DNA circularization protein N (64 kDa virion protein) (Gene product 43) (gp43) (Gene product N) ...
BP44_BPMU Baseplate hub protein gp44 (43 kDa tail protein) (Gene product 44) (gp44) (Gene product P) (gpP)
BP45_BPMU Baseplate puncturing device gp45 (Baseplate spike protein) (Gene product 45) (gp45) (Gene product Q) ...
BP47_BPMU Baseplate protein gp47 (Gene product 47) (gp47) (Gene product W) (gpW)
CAPSD_BPMU Major capsid protein (Gene product 34) (gp34) (Gene product T) (gpT) (Major head protein)
BP48_BPMU Baseplate protein gp48 (Gene product 48) (gp48) (Gene product R) (gpR)
BP46_BPMU Baseplate protein gp46 (Gene product 46) (gp46) (Gene product V) (gpV)
U2_BPMU Tail fiber assembly protein U' (Gene product U') (gpU')
U1_BPMU Tail fiber assembly protein U (Gene product 50) (gp50) (Gene product U) (gpU)
VG20_BPMU Uncharacterized protein gp20 (Gene product 20) (gp20)

9 entries

Escherichia phage D108 (Bacteriophage D108)

MOM_BPD10 Adenine modification enzyme mom (Adenine acetyltransferase) (EC 2.3.1.-) (Gene product mom) (gpMom) ...
NER_BPD10 Negative regulator of transcription (Ner)
E15_BPD10 Uncharacterized protein gp14 (E15) (Gene product 14) (gp14)
GIN_BPD10 Serine recombinase gin (EC 3.1.22.-) (EC 6.5.1.-) (G-segment invertase) (Gin)
GES_BPD10 D108-specific protein (12 kDa protein)
GEMA_BPD10 GemA protein (Gene product 16) (gp16)
REPC_BPD10 Repressor c protein (Repc) (CI)
TARGB_BPD10 ATP-dependent target DNA activator B (EC (Gene product B) (gpB) (MuB)
COM_BPD10 Translational activator com (Gene product com) (gpCom)