Retroviral matrix protein
Retroviral matrix proteins are components of envelope-associated capsids of retroviruses. These proteins line the inner surface of viral envelopes and are associated with viral membranes.{{cite journal |vauthors=Conte MR, Matthews S | title = Retroviral matrix proteins: a structural perspective | journal = Virology | volume = 246 | issue = 2 | pages = 191–8 |date=July 1998 | pmid = 9657938 | doi = 10.1006/viro.1998.9206 | doi-access = free }}
Matrix proteins are produced as N-terminal domains of Gag precursor polyproteins. The Gag polyprotein directs the assembly and release of virus particles from infected cells. The Gag polyprotein has three domains required for activity: an N-terminal membrane-binding (M) domain (which corresponds to the matrix protein) that directs Gag to the plasma membrane, an interaction (I) domain involved in Gag aggregation, and a late assembly (L) domain that mediates the budding process .{{cite journal |vauthors=Parent LJ, Cairns TM, Albert JA, Wilson CB, Wills JW, Craven RC | title = RNA dimerization defect in a Rous sarcoma virus matrix mutant | journal = J. Virol. | volume = 74 | issue = 1 | pages = 164–72 |date=January 2000 | pmid = 10590103 | pmc = 111525 | doi = 10.1128/jvi.74.1.164-172.2000}} During viral maturation, the Gag polyprotein is cleaved by the retroviral protease into several corresponding structural proteins, yielding the matrix (MA), capsid (CA), and nucleocapsid (NC) proteins, and some smaller peptides. Gag-derived proteins govern the entire assembly and release of the virus particles, with matrix proteins playing key roles in Gag stability, capsid assembly, transport and budding.
Families of retroviral matrix proteins
{{Infobox protein family
| Symbol = Gag_MA
| Name = Gag_MA
| image = PDB 1mn8 EBI.jpg
| width =
| caption = structure of moloney murine leukaemia virus matrix protein
| Pfam = PF01140
| Pfam_clan = CL0074
| InterPro = IPR000840
| SMART =
| PROSITE =
| MEROPS =
| SCOP = 1mn8
| TCDB =
| OPM family = 42
| OPM protein = 1mn8
| CAZy =
| CDD =
}}
Although matrix proteins from different viruses appear to perform similar functions and can have similar structural folds, their primary sequences can be very different. Typical matrix proteins of retroviruses form an alpha helical bundle structure .{{cite journal |vauthors=McDonnell JM, Fushman D, Cahill SM, Zhou W, Wolven A, Wilson CB, Nelle TD, Resh MD, Wills J, Cowburn D | title = Solution structure and dynamics of the bioactive retroviral M domain from Rous sarcoma virus | journal = J. Mol. Biol. | volume = 279 | issue = 4 | pages = 921–8 |date=June 1998 | pmid = 9642071 | doi = 10.1006/jmbi.1998.1788 }}
One family of these proteins represents matrix proteins from gammaretroviruses, such as Moloney murine leukemia virus (MoMLV), feline leukemia virus (FLV), and feline sarcoma virus (FESV).{{cite journal |vauthors=Riffel N, Harlos K, Iourin O, Rao Z, Kingsman A, Stuart D, Fry E | title = Atomic resolution structure of Moloney murine leukemia virus matrix protein and its relationship to other retroviral matrix proteins | journal = Structure | volume = 10 | issue = 12 | pages = 1627–36 |date=December 2002 | pmid = 12467570 | doi = 10.1016/S0969-2126(02)00896-1| doi-access = free }}{{cite journal |vauthors=Baker SJ, Cosenza SC, Reddy EP | title = The role of v-Fgr myristoylation and the Gag domain in membrane binding and cellular transformation | journal = Virology | volume = 249 | issue = 1 | pages = 1–11 |date=September 1998 | pmid = 9740771 | doi = 10.1006/viro.1998.9323 | doi-access = free }} This family also includes matrix proteins from several eukaryotic endogenous retroviruses, which arise when one or more copies of the retroviral genome becomes integrated into the host genome.{{cite journal |vauthors=Gifford R, Tristem M | title = The evolution, distribution and diversity of endogenous retroviruses | journal = Virus Genes | volume = 26 | issue = 3 | pages = 291–315 |date=May 2003 | pmid = 12876457 | doi = 10.1023/A:1024455415443| s2cid = 34639116 }}
{{Infobox protein family
| Symbol = Retro_M
| Name = Retro_M
| image = PDB 1a6s EBI.jpg
| width =
| caption = m-domain from gag polyprotein of rous sarcoma virus, nmr, 20 structures
| Pfam = PF02813
| Pfam_clan = CL0074
| InterPro = IPR004028
| SMART =
| PROSITE =
| MEROPS =
| SCOP = 1a6s
| TCDB =
| OPM family = 42
| OPM protein = 1a6s
| CAZy =
| CDD =
}}
Another family represents the M domain of the Gag polyprotein found in avian retroviruses. It includes Gag polyproteins from several avian endogenous retroviruses.{{cite journal | author = Borisenko L | title = Avian endogenous retroviruses | journal = Folia Biol. (Praha) | volume = 49 | issue = 5 | pages = 177–82 | year = 2003 | doi = 10.14712/fb2003049050177 | pmid = 14680291 }}
{{Infobox protein family
| Symbol = Gag_p10
| Name = Gag_p10
| image = PDB 2f76 EBI.jpg
| width =
| caption = solution structure of the m-pmv wild type matrix protein (p10)
| Pfam = PF02337
| Pfam_clan = CL0074
| InterPro = IPR003322
| SMART =
| PROSITE =
| MEROPS =
| SCOP =
| TCDB =
| OPM family = 44
| OPM protein = 2lpy
| CAZy =
| CDD =
}}
Matrix proteins are also components of beta-retroviruses such as Mason-Pfizer monkey virus (MPMV) and mouse mammary tumor virus (MMTV) .{{cite journal |vauthors=Stansell E, Tytler E, Walter MR, Hunter E | title = An early stage of Mason-Pfizer monkey virus budding is regulated by the hydrophobicity of the Gag matrix domain core | journal = J. Virol. | volume = 78 | issue = 10 | pages = 5023–31 |date=May 2004 | pmid = 15113883 | pmc = 400380 | doi = 10.1128/jvi.78.10.5023-5031.2004}}{{cite journal |vauthors=Poon DT, Li G, Aldovini A | title = Nucleocapsid and matrix protein contributions to selective human immunodeficiency virus type 1 genomic RNA packaging | journal = J. Virol. | volume = 72 | issue = 3 | pages = 1983–93 |date=March 1998 | pmid = 9499052 | pmc = 109491 | doi = 10.1128/JVI.72.3.1983-1993.1998}} This entry also identifies matrix proteins from several eukaryotic endogenous retroviruses.
{{Infobox protein family
| Symbol = Gag_p15
| Name = Gag_p15
| image = PDB 1hek EBI.jpg
| width =
| caption = crystal structure of equine infectious anaemia virus matrix antigen (eiav ma)
| Pfam = PF08723
| Pfam_clan =
| InterPro = IPR014834
| SMART =
| PROSITE =
| MEROPS =
| SCOP = 1hek
| TCDB =
| OPM family = 44
| OPM protein = 1hek
| CAZy =
| CDD =
}}
References
{{reflist}}
{{InterPro content|IPR000840}}
{{Viral proteins}}