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

S2_BPMU Tail fiber protein S' (Gene product S') (gpS')
PRO_BPMU Protease I (Gene product 32) (gp32) (Gene product I) (gpI)
GP25_BPMU Uncharacterized protein gp25 (Gene product 25) (gp25)
S1_BPMU Tail fiber protein S (Gene product 49) (gp49) (Gene product S) (gpS)
TAP_BPMU Probable tail assembly protein gp41 (Gene product 41) (gp41) (Tail assembly chaperone)
REPC_BPMU Repressor protein c (Repc) (CI) (Gene product 1) (gp1) (Mu repressor) (MuR)
TNPA_BPMU DDE-recombinase A (EC 3.1.22.-) (EC 6.5.1.-) (DDE-transposase A) (Gene product 03) (gp03) (Gene ...
TAPFS_BPMU Probable tail assembly protein FS-gp41
TARGB_BPMU ATP-dependent target DNA activator B (EC 3.6.1.-) (Gene product 04) (gp04) (Gene product B) (gpB) ...
TUBE_BPMU Tail tube protein (TTP) (Gene product 40) (gp40) (Gene product M) (gpM)
SPAN1_BPMU Probable spanin, inner membrane subunit (i-spanin) (gene product 23) (gp23)
MOR_BPMU Middle operon regulator (Mor) (GemB) (Gene product 17) (gp17)
GP18_BPMU Uncharacterized protein gp18 (E18) (E18 protein) (Gene product 18)
PORTL_BPMU Portal protein (Gene product 29) (gp29) (Gene product H) (gpH) (Head-tail connector)
MOM_BPMU Methylcarbamoylase mom (Adenine modification enzyme mom) (Gene product 55) (gp55) (Gene product mom) ...
U1_BPMU Tail fiber assembly protein U (Gene product 50) (gp50) (Gene product U) (gpU)
GP38_BPMU Putative sheath terminator protein (Gene product 38) (gp38)
GPG_BPMU Putative capsid assembly protein G (Gene product G) (gpG)
GP24_BPMU Uncharacterized protein gp24 (Gene product 24) (gp24)
GP19_BPMU Uncharacterized protein gp19 (E19 protein) (Gene product 19) (gp19)
GAM_BPMU Putative DNA ends protecting protein gam (Gene product 10) (gp10)
GP15_BPMU Uncharacterized protein gp15 (Gene product 15) (gp15)
GP14_BPMU Uncharacterized protein gp14 (E15) (Gene product 14) (gp14)
GP6_BPMU Uncharacterized protein gp6 (E5) (Gene product 6) (gp6)
GP7_BPMU Uncharacterized protein gp7 (E6) (Gene product 7) (gp7)
GP8_BPMU Uncharacterized protein gp8 (E7) (Gene product 8) (gp8)
GP9_BPMU Uncharacterized protein gp9 (E8) (Gene product 9) (gp9)
ENLYS_BPMU SAR-endolysin (EC (Endolysin) (Gene product 22) (gp22) (Lysis protein) (Lysozyme) ...
GP13_BPMU Uncharacterized protein gp13 (E14) (Gene product 13) (gp13)
CAPSD_BPMU Major capsid protein (Gene product 34) (gp34) (Gene product T) (gpT) (Major head protein)
GP35_BPMU Uncharacterized protein gp35 (Gene product 35) (gp35)
GPF_BPMU Putative capsid assembly protein F (Gene product 30) (gp30) (Gene product F) (gpF)
GP26_BPMU Uncharacterized protein gp26 (Gene product 26) (gp26)
GP12_BPMU Uncharacterized protein gp12 (E13) (Gene product 12) (gp12)
GPJ_BPMU Gene product J (gpJ) (Gene product 36) (gp36)
BP46_BPMU Baseplate protein gp46 (Gene product 46) (gp46) (Gene product V) (gpV)
CIRCN_BPMU DNA circularization protein N (64 kDa virion protein) (Gene product 43) (gp43) (Gene product N) ...
GIN_BPMU Serine recombinase gin (EC 3.1.22.-) (EC 6.5.1.-) (G-segment invertase) (Gin) (Gene product 53) ...
KIL_BPMU Protein kil (Gene product 5) (gp5) (Protein cim)
GP11_BPMU Uncharacterized protein gp11 (Gene product 11) (gp11)
BP48_BPMU Baseplate protein gp48 (Gene product 48) (gp48) (Gene product R) (gpR)
ACTC_BPMU Late transcription activator C (C) (Gene product 21) (gp21) (Protein C)
BP45_BPMU Baseplate puncturing device gp45 (Baseplate spike protein) (Gene product 45) (gp45) (Gene product Q) ...
BP44_BPMU Baseplate hub protein gp44 (43 kDa tail protein) (Gene product 44) (gp44) (Gene product P) (gpP)
BP47_BPMU Baseplate protein gp47 (Gene product 47) (gp47) (Gene product W) (gpW)
COM_BPMU Translational activator com (Gene product 54) (gp54) (Gene product com) (gpCom)
GEMA_BPMU GemA protein (Gene product 16) (gp16)
NER_BPMU Negative regulator of transcription (Ner) (Gene product 2) (gp2)
TMP_BPMU Probable tape measure protein (TMP) (Gene product 42) (gp42) (Gene product Y) (gpY)
TSP_BPMU Tail sheath protein (TSP) (Gene product 39) (gp39) (Gene product L) (gpL)
U2_BPMU Tail fiber assembly protein U' (Gene product U') (gpU')
TRP_BPMU Probable tail terminator protein (TrP) (Gene product 37) (gp37) (Gene product K) (gpK)
VG20_BPMU Uncharacterized protein gp20 (Gene product 20) (gp20)
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) ...

9 entries

Escherichia phage D108 (Bacteriophage D108)

TARGB_BPD10 ATP-dependent target DNA activator B (EC 3.6.1.-) (Gene product B) (gpB) (MuB)
MOM_BPD10 Methylcarbamoylase mom (Adenine modification enzyme mom) (Gene product mom) (gpMom) (Modification of ...
REPC_BPD10 Repressor c protein (Repc) (CI)
E15_BPD10 Uncharacterized protein gp14 (E15) (Gene product 14) (gp14)
GEMA_BPD10 GemA protein (Gene product 16) (gp16)
GES_BPD10 D108-specific protein (12 kDa protein)
COM_BPD10 Translational activator com (Gene product com) (gpCom)
GIN_BPD10 Serine recombinase gin (EC 3.1.22.-) (EC 6.5.1.-) (G-segment invertase) (Gin)
NER_BPD10 Negative regulator of transcription (Ner)