MA - Matrix protein
HIV MA stabilizes the viral particle by remaining attached to the inner surface of the virion lipid bilayer after viral maturation.
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[animated gif: 320x240 ]
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Isoforms:
Cleavage site:
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Localization:
- inner surface of virion lipid bilayer
- cytoplasm
- nuclear membrane
- nucleus
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Function:
- structural protein
- stabilizes viral particles
- associates with complex that escorts vDNA to the nucleus (Ref. #4)
- facilitates nuclear transport of vDNA, due to a karyophilic signal that is recognized by cellular nuclear import machinery (Ref. #5)
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Additional
Information:
- MA is derived from the myristylated N-terminus of p55
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Genomic Location: [TOP]
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Reference
Sequences:
HIV-1
(HXB2):
10 20 30 40 50 60 70
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MGARASVLSG GELDRWEKIR LRPGGKKKYK LKHIVWASRE LERFAVNPGL LETSEGCRQI LGQLQPSLQT
80 90 100 110 120 130
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GSEELRSLYN TVATLYCVHQ RIEIKDTKEA LDKIEEEQNK SKKKAQQAAA DTGHSNQVSQ NY
[download in fasta format]
Length:
132 amino acids (Gag polyprotein: residues 1 - 132)
Molecular Weight: 14779 Da
Theoretical pI: 9.28
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Protein Domains/Folds/Motifs: [TOP]
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InterPro signature for Retroviral Matrix protein p17 - IPR000071
- The structure of the protein consists of 5 α-helices, a short 3.10 helix, and a 3-stranded mixed β-sheet (Ref. #6)
- The first 3 α-helices and the 3.10 helix surround the 4th α-helix, forming a globular domain capped by the β-sheet
- The 5th (C-terminal) α-helix projects away from the β-sheet to expose the C-terminal residues
- Basic residues, that function in membrane-binding and nuclear localization, cluster around the cationic loop that connects β-strands 1 and 2
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Secondary Structure prediction:
Coiled Coil Region - ncoils:
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N-glycosylation:
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N-myristoylation:
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Amidation:
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Protein kinase C:
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Casein kinase II:
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Tyrosine kinase:
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cAMP / cGMP kinase:
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Cell attachment motif:
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Asp Protease motif:
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Asp Prot Retro motif:
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Cysteine-rich Region:
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Tryptophan-rich Region:
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Zinc-finger CCHC motif:
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Leucine Zipper motif:
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Protein-Protein Interactions: [TOP]
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- Matrix binds to karyopherins for nuclear import
- Matrix binds to Vpr for nuclear import
- Matrix binds to gp41 for incorporation into virion
- Matrix binds to HO3 to enhance infectivity of released virus particles
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Primary and Secondary Database Entries: [TOP]
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Identifiers:
PDB/MMDB: Search for HIV-1 & Matrix
SwissProt: P04591 (HIV-1 HXB2 GAG)
EMBL: K03455; AAB50258.1 [EMBL/GenBank/DDBJ]
PIR: UNKNOWN
HIV: K03455; UNKNOWN$HXB2
InterPro: IPR000071 -
Pfam: PF00540 -
Prints: PR00234
ProDom:
PD000202 (1 - 131)
SCOP: SSF47836 Retroviral matrix protein
BLOCKS: P04591
Prosite: P04591
ProtoNet: P04591
ProtoMap: P04591
PRESAGE: P04591
Database of Interacting Proteins: P04591
ModBase: P04591
Swiss-2DPAGE: 2D gel
- BioAfrica Tools:
- - Gag Protein Data Mining Tool provides real-time analysis of HIV-1 Gag isolates
- - HIV Structure BLAST searches for similar HIV sequences that have known structures
- - HIV Proteomics Resource contains protein sequence and structure analysis tools
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Reviews and References: [TOP]
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- 1 - HIV Sequence Compendium 2000
- Kuiken CL, Foley B, Hahn B, Korber B, Marx PA, McCutchan F, Mellors JW, Mullins JI, Sodroski J, Wolinksy S.
- Theoretical Biol. & Biophys. Group, Los Alamos Nat Lab, LA-UR 01-3860 [Read it online: Compendium]
- 2 - Retroviruses
- Coffin JM, Hughes SH, Varmus HE.
- CD-ROM ed. (2002) Cold Spring Harbor Laboratory Press [Read it online: NCBI Bookshelf]
- 3 - Molecular Characteristics of HIV-1 Subtype C Viruses from KwaZulu-Natal, South Africa:
- Implications for Vaccine and Antiretroviral Control Strategies.
- Gordon M, De Oliveira T, Bishop K, Coovadia HM, Madurai L, Engelbrecht S, Janse van Rensburg E, Mosam A, Smith A, Cassol S.
- Journal of Virology 77(4): 2587-2599 (2003) [pubmed: 12551997]
- 4 - HIV nuclear import is governed by the phosphotyrosine-mediated binding of matrix to the
- core domain of integrase.
- Gallay P, Swingler S, Song J.
- Cell 83: 569-576 (1995) [pubmed: 7585960]
- 5 - Human immunodeficiency virus infection of cells arrested in the cell cycle.
- Lewis P, Hensel M, Emerman M.
- EMBO J 11: 3053-3058 (1992) [pubmed: 1322294]
- 6 - Three-dimensional structure of the human immunodeficiency virus type 1 matrix protein.
- Massiah MA, Starich MR, Paschall C, Summers MF, Christensen AM, Sundquist WI.
- J Mol Biol 244: 198-223 (1994) [pubmed: 7966331]
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