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P11077 (MU1_REOVL) Reviewed, UniProtKB/Swiss-Prot

Last modified April 3, 2013. Version 94. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
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Names and origin

Protein namesRecommended name:
Outer capsid protein mu-1
Short name=Mu1

Cleaved into the following 2 chains:

  1. Outer capsid protein mu-1N
  2. Outer capsid protein mu-1C
Gene names
Name:M2
OrganismReovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) [Reference proteome]
Taxonomic identifier10884 [NCBI]
Taxonomic lineageViruses › dsRNA viruses › Reoviridae › Spinareovirinae › Orthoreovirus ›
Virus hostMammalia [TaxID: 40674]

Protein attributes

Sequence length708 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Major outer capsid protein involved in host cell membrane penetration. In the endocytic compartment, outer-capsid protein sigma-3 is removed by cathepsin proteases, which exposes the viral membrane-penetration protein mu-1. Both myristoylated peptides mu-1N and phi are released during infectious subvirion particles (ISVP) formation in the endosome. They associate with host membranes and mu-1N induces permeabilization and delivery of transcriptionally active viral particles into the host cell cytoplasm. Seems to induce apoptosis in the host cell. Ref.5 Ref.6 Ref.7 Ref.8 Ref.9

The viral outer shell polypeptides, of which mu-1 is one, impose structural constraints that prevent elongation of nascent transcripts by the RNA-dependent RNA polymerase lambda-3. Ref.5 Ref.6 Ref.7 Ref.8 Ref.9

Subunit structure

Heterohexamer of three sigma-3 and three Mu-1 proteins.

Subcellular location

Outer capsid protein mu-1: Virion. Host cell membrane; Lipid-anchor By similarity. Host endoplasmic reticulum. Host mitochondrion. Note: Found in the outer capsid. Seems to associate with cell membranes. This association is enhanced by myristoylation By similarity. Ref.7

Domain

The C-terminal region, phi, determines both targeting to intracellular membranes and induction of apoptosis Probable.

Post-translational modification

Cleaved during the endosomal proteolytic disassembly of the outer capsid. Mu-1 is proteolytically cleaved into mu-1N and mu-1C during the maturation step to generate the ISVP. Cleavage of mu-1 to mu-1C is dependent on myristoylation and binding to sigma-3 protein. Mu-1C is further cleaved into delta (59 kDa), and phi (13 kDa) segments during entry into the host cell cytoplasm. Ref.4

Mu-1 and mu-1N are N-terminally myristoylated. This acylation is essential for the membrane fusion activity By similarity.

Sequence similarities

Belongs to the orthoreovirus mu-1 protein family.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Initiator methionine11Removed; by host By similarity
Chain2 – 708707Outer capsid protein mu-1
PRO_0000040662
Chain2 – 4241Outer capsid protein mu-1N
PRO_0000344980
Chain43 – 708666Outer capsid protein mu-1C
PRO_0000040664

Sites

Site42 – 432Cleavage By similarity

Amino acid modifications

Lipidation21N-myristoyl glycine; by host By similarity
Glycosylation121N-linked (GlcNAc...); by host Potential
Glycosylation811N-linked (GlcNAc...); by host Potential
Glycosylation1101N-linked (GlcNAc...); by host Potential
Glycosylation4581N-linked (GlcNAc...); by host Potential
Glycosylation4821N-linked (GlcNAc...); by host Potential
Glycosylation5281N-linked (GlcNAc...); by host Potential
Glycosylation6591N-linked (GlcNAc...); by host Potential

Experimental info

Mutagenesis421N → A: Complete loss of mu-1N cleavage and host membrane penetration. Ref.6 Ref.9
Sequence conflict31N → T in AAA47237. Ref.1
Sequence conflict237 – 2382AV → LL in AAA47237. Ref.1
Sequence conflict2721P → L in AAA47236. Ref.2
Sequence conflict2841K → R in AAA47236. Ref.2
Sequence conflict6441V → M in AAA47237. Ref.1

Secondary structure

1 .............................................................................................................. 708
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
P11077 [UniParc].

Last modified July 22, 2008. Version 4.
Checksum: 12F3839798DF355F

FASTA70876,233
        10         20         30         40         50         60 
MGNASSIVQT INVTGDGNVF KPSAETSSTA VPSLSLSPGM LNPGGVPWIA IGDETSVTSP 

        70         80         90        100        110        120 
GALRRMTSKD IPETAIINTD NSSGAVPSES ALVPYNDEPL VVVTEHAIAN FTKAEMALEF 

       130        140        150        160        170        180 
NREFLDKLRV LSVSPKYSDL LTYVDCYVGV SARQALNNFQ KQVPVITPTR QTMYVDSIQA 

       190        200        210        220        230        240 
ALKALEKWEI DLRVAQTLLP TNVPIGEVSC PMQSVVKLLD DQLPDDSLIR RYPKEAAVAL 

       250        260        270        280        290        300 
AKRNGGIQWM DVSEGTVMNE AVNAVAASAL APSASAPPLE EKSKLTEQAM DLVTAAEPEI 

       310        320        330        340        350        360 
IASLVPVPAP VFAIPPKPAD YNVRTLKIDE ATWLRMIPKT MGTPFQIQVT DNTGTNWHLN 

       370        380        390        400        410        420 
LRGGTRVVNL DQIAPMRFVL DLGGKSYKET SWDPNGKKVG FIVFQSKIPF ELWTAASQIG 

       430        440        450        460        470        480 
QATVVNYVQL YAEDSSFTAQ SIIATTSLAY NYEPEQLNKT DPEMNYYLLA TFIDSAAITP 

       490        500        510        520        530        540 
TNMTQPDVWD ALLTMSPLSA GEVTVKGAVV SEVVPAELIG SYTPESLNAS LPNDAARCMI 

       550        560        570        580        590        600 
DRASKIAEAI KIDDDAGPDE YSPNSVPIQG QLAISQLETG YGVRIFNPKG ILSKIASRAM 

       610        620        630        640        650        660 
QAFIGDPSTI ITQAAPVLSD KNNWIALAQG VKTSLRTKSL SAGVKTAVSK LSSSESIQNW 

       670        680        690        700 
TQGFLDKVST HFPAPKPDCP TNGDGSEPSA RRVKRDSYAG VVKRGYTR

« Hide

References

[1]"Molecular cloning and sequencing of the gene (M2) encoding the major virion structural protein (mu 1-mu 1C) of serotypes 1 and 3 of mammalian reovirus."
Tarlow O., McCorquodale J.G., McCrae M.A.
Virology 164:141-146(1988) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[2]"Evolution of reovirus genes: a comparison of serotype 1, 2, and 3 M2 genome segments, which encode the major structural capsid protein mu 1C."
Wiener J.R., Joklik W.K.
Virology 163:603-613(1988) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[3]"In vitro recoating of reovirus cores with baculovirus-expressed outer-capsid proteins mu1 and sigma3."
Chandran K., Walker S.B., Chen Y., Contreras C.M., Schiff L.A., Baker T.S., Nibert M.L.
J. Virol. 73:3941-3950(1999) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA].
Strain: Isolate T1/Human/Ohio/1953.
[4]"A carboxy-terminal fragment of protein mu 1/mu 1C is present in infectious subvirion particles of mammalian reoviruses and is proposed to have a role in penetration."
Nibert M.L., Fields B.N.
J. Virol. 66:6408-6418(1992) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEOLYTIC PROCESSING.
[5]"Transcriptional activities of reovirus RNA polymerase in recoated cores. Initiation and elongation are regulated by separate mechanisms."
Farsetta D.L., Chandran K., Nibert M.L.
J. Biol. Chem. 275:39693-39701(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[6]"Putative autocleavage of outer capsid protein micro1, allowing release of myristoylated peptide micro1N during particle uncoating, is critical for cell entry by reovirus."
Odegard A.L., Chandran K., Zhang X., Parker J.S.L., Baker T.S., Nibert M.L.
J. Virol. 78:8732-8745(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, MUTAGENESIS OF ASN-42.
[7]"Reovirus outer capsid protein micro1 induces apoptosis and associates with lipid droplets, endoplasmic reticulum, and mitochondria."
Coffey C.M., Sheh A., Kim I.S., Chandran K., Nibert M.L., Parker J.S.L.
J. Virol. 80:8422-8438(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, SUBCELLULAR LOCATION.
[8]"Reovirus mu1 structural rearrangements that mediate membrane penetration."
Zhang L., Chandran K., Nibert M.L., Harrison S.C.
J. Virol. 80:12367-12376(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[9]"Peptides released from reovirus outer capsid form membrane pores that recruit virus particles."
Ivanovic T., Agosto M.A., Zhang L., Chandran K., Harrison S.C., Nibert M.L.
EMBO J. 27:1289-1298(2008) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, MUTAGENESIS OF ASN-42.
[10]"Structure of the reovirus membrane-penetration protein, Mu1, in a complex with is protector protein, Sigma3."
Liemann S., Chandran K., Baker T.S., Nibert M.L., Harrison S.C.
Cell 108:283-295(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (2.8 ANGSTROMS) IN COMPLEX WITH SIGMA-3.
[11]"Features of reovirus outer capsid protein mu1 revealed by electron cryomicroscopy and image reconstruction of the virion at 7.0 Angstrom resolution."
Zhang X., Ji Y., Zhang L., Harrison S.C., Marinescu D.C., Nibert M.L., Baker T.S.
Structure 13:1545-1557(2005) [PubMed] [Europe PMC] [Abstract]
Cited for: STRUCTURE BY ELECTRON MICROSCOPY (7.0 ANGSTROMS).

Cross-references

Sequence databases

EMBL
GenBank
DDBJ		M19407 Genomic RNA. Translation: AAA47237.1.
M19345 mRNA. Translation: AAA47236.1.
AF490617 mRNA. Translation: AAM10735.1.
PIRM2XR2L. A28607.
M2XR1L. A28612.

3D structure databases

PDBe
RCSB PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
1JMUX-ray2.80A/C/E2-42[»]
B/D/F43-708[»]
2CSEelectron microscopy7.00A/B/C/J/K/L/P/Q/R/T1-708[»]
ProteinModelPortalP11077.
SMRP11077. Positions 10-675.
ModBaseSearch...

Protein-protein interaction databases

IntActP11077. 1 interaction.

Protein family/group databases

MEROPSN07.001.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D1.10.2040.10. 2 hits.
2.60.120.420. 1 hit.
3.90.1370.10. 1 hit.
InterProIPR009113. Mu1/VP4.
IPR015962. Mu1_membr_pen_a-bundle_sub2.
IPR015961. Mu1_membr_pen_a/b_sub.
IPR015960. Mu1_membr_pen_b-sand_sub.
[Graphical view]
PfamPF05993. Reovirus_M2. 1 hit.
[Graphical view]
SUPFAMSSF69908. Mu1_membr_pen. 1 hit.
ProtoNetSearch...

Other

EvolutionaryTraceP11077.

Entry information

Entry nameMU1_REOVL
AccessionPrimary (citable) accession number: P11077
Secondary accession number(s): Q85657, Q8QR20
Entry history
Integrated into UniProtKB/Swiss-Prot: July 1, 1989
Last sequence update: July 22, 2008
Last modified: April 3, 2013
This is version 94 of the entry and version 4 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Relevant documents

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

SIMILARITY comments

Index of protein domains and families

to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·Documents