Skip to main content
Journal of Virology logoLink to Journal of Virology
. 1995 Jul;69(7):4213–4227. doi: 10.1128/jvi.69.7.4213-4227.1995

Genetic analysis of the major homology region of the Rous sarcoma virus Gag protein.

R C Craven 1, A E Leure-duPree 1, R A Weldon Jr 1, J W Wills 1
PMCID: PMC189159  PMID: 7769681

Abstract

The mature cores of all retroviruses contain a major structural protein known as the CA (capsid) protein. Although it appears to form a shell around the ribonucleoprotein complex that contains the viral RNA, its function in viral replication is largely unknown. Little sequence similarity exists between the CA proteins of different retroviruses, except for a region of about 20 amino acids termed the major homology region (MHR). To examine the role of the CA protein in particle assembly and release, mutants of Rous sarcoma virus were created in which segments of CA were deleted or single conserved residues in the MHR were altered. The ability of the deletion mutants to release particles at rates similar to the wild-type protein demonstrated that the CA domain of Gag is not an essential component of the minimal budding machinery. Certain point mutations in the MHR region did block assembly and release in certain cell types, presumably by perturbing the global structure of the Gag precursor. Another group of MHR substitutions produced noninfectious or poorly infectious particles that were normal in their content of gag and pol gene products and viral RNA. The mutants were capable of initiating reverse transcription in vitro; however, the association of CA protein with the core was compromised, as indicated by its sensitivity to extraction with nonionic detergent. Prominent blebs on the virion envelope also indicated a disturbance at the membrane. Finally, an anti-peptide serum directed against MHR was found to react with the uncleaved Gag protein but not with mature CA, suggesting that MHR undergoes a dynamic rearrangement upon liberation from the polyprotein. We conclude that the MHR is involved in the very late steps in maturation of the virion (i.e., ones that occur after budding is initiated) and is essential for proper function of the core upon entry into a new host cell.

Full Text

The Full Text of this article is available as a PDF (2.2 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bennett R. P., Nelle T. D., Wills J. W. Functional chimeras of the Rous sarcoma virus and human immunodeficiency virus gag proteins. J Virol. 1993 Nov;67(11):6487–6498. doi: 10.1128/jvi.67.11.6487-6498.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bennett R. P., Rhee S., Craven R. C., Hunter E., Wills J. W. Amino acids encoded downstream of gag are not required by Rous sarcoma virus protease during gag-mediated assembly. J Virol. 1991 Jan;65(1):272–280. doi: 10.1128/jvi.65.1.272-280.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bolognesi D. P., Luftig R., Shaper J. H. Localization of RNA tumor virus polypeptides. I. Isolation of further virus substructures. Virology. 1973 Dec;56(2):549–564. doi: 10.1016/0042-6822(73)90057-3. [DOI] [PubMed] [Google Scholar]
  4. Boone L. R., Myer F. E., Yang D. M., Ou C. Y., Koh C. K., Roberson L. E., Tennant R. W., Yang W. K. Reversal of Fv-1 host range by in vitro restriction endonuclease fragment exchange between molecular clones of N-tropic and B-tropic murine leukemia virus genomes. J Virol. 1983 Oct;48(1):110–119. doi: 10.1128/jvi.48.1.110-119.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bowerman B., Brown P. O., Bishop J. M., Varmus H. E. A nucleoprotein complex mediates the integration of retroviral DNA. Genes Dev. 1989 Apr;3(4):469–478. doi: 10.1101/gad.3.4.469. [DOI] [PubMed] [Google Scholar]
  6. Buchholz C. J., Spehner D., Drillien R., Neubert W. J., Homann H. E. The conserved N-terminal region of Sendai virus nucleocapsid protein NP is required for nucleocapsid assembly. J Virol. 1993 Oct;67(10):5803–5812. doi: 10.1128/jvi.67.10.5803-5812.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Chazal N., Carrière C., Gay B., Boulanger P. Phenotypic characterization of insertion mutants of the human immunodeficiency virus type 1 Gag precursor expressed in recombinant baculovirus-infected cells. J Virol. 1994 Jan;68(1):111–122. doi: 10.1128/jvi.68.1.111-122.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Clare J., Farabaugh P. Nucleotide sequence of a yeast Ty element: evidence for an unusual mechanism of gene expression. Proc Natl Acad Sci U S A. 1985 May;82(9):2829–2833. doi: 10.1073/pnas.82.9.2829. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Cooper G. M., Okenquist S. Mechanism of transfection of chicken embryo fibroblasts by Rous sarcoma virus DNA. J Virol. 1978 Oct;28(1):45–52. doi: 10.1128/jvi.28.1.45-52.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Craven R. C., Bennett R. P., Wills J. W. Role of the avian retroviral protease in the activation of reverse transcriptase during virion assembly. J Virol. 1991 Nov;65(11):6205–6217. doi: 10.1128/jvi.65.11.6205-6217.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Craven R. C., Leure-duPree A. E., Erdie C. R., Wilson C. B., Wills J. W. Necessity of the spacer peptide between CA and NC in the Rous sarcoma virus gag protein. J Virol. 1993 Oct;67(10):6246–6252. doi: 10.1128/jvi.67.10.6246-6252.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Curran J., Homann H., Buchholz C., Rochat S., Neubert W., Kolakofsky D. The hypervariable C-terminal tail of the Sendai paramyxovirus nucleocapsid protein is required for template function but not for RNA encapsidation. J Virol. 1993 Jul;67(7):4358–4364. doi: 10.1128/jvi.67.7.4358-4364.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Davis N. L., Rueckert R. R. Properties of a ribonucleoprotein particle isolated from Nonidet P-40-treated Rous sarcoma virus. J Virol. 1972 Nov;10(5):1010–1020. doi: 10.1128/jvi.10.5.1010-1020.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Delassus S., Sonigo P., Wain-Hobson S. Genetic organization of gibbon ape leukemia virus. Virology. 1989 Nov;173(1):205–213. doi: 10.1016/0042-6822(89)90236-5. [DOI] [PubMed] [Google Scholar]
  15. DesGroseillers L., Jolicoeur P. Physical mapping of the Fv-1 tropism host range determinant of BALB/c murine leukemia viruses. J Virol. 1983 Dec;48(3):685–696. doi: 10.1128/jvi.48.3.685-696.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Dong J. Y., Dubay J. W., Perez L. G., Hunter E. Mutations within the proteolytic cleavage site of the Rous sarcoma virus glycoprotein define a requirement for dibasic residues for intracellular cleavage. J Virol. 1992 Feb;66(2):865–874. doi: 10.1128/jvi.66.2.865-874.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Erdie C. R., Wills J. W. Myristylation of Rous sarcoma virus Gag protein does not prevent replication in avian cells. J Virol. 1990 Oct;64(10):5204–5208. doi: 10.1128/jvi.64.10.5204-5208.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Fernandez-Tomas C. B., Baltimore D. Morphogenesis of poliovirus. II. Demonstration of a new intermediate, the proviron. J Virol. 1973 Nov;12(5):1122–1130. doi: 10.1128/jvi.12.5.1122-1130.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Gallagher T. M., Rueckert R. R. Assembly-dependent maturation cleavage in provirions of a small icosahedral insect ribovirus. J Virol. 1988 Sep;62(9):3399–3406. doi: 10.1128/jvi.62.9.3399-3406.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Garvey K. J., Oberste M. S., Elser J. E., Braun M. J., Gonda M. A. Nucleotide sequence and genome organization of biologically active proviruses of the bovine immunodeficiency-like virus. Virology. 1990 Apr;175(2):391–409. doi: 10.1016/0042-6822(90)90424-p. [DOI] [PubMed] [Google Scholar]
  21. Goff S. P., Lobel L. I. Mutants of murine leukemia viruses and retroviral replication. Biochim Biophys Acta. 1987 Jul 8;907(2):93–123. doi: 10.1016/0304-419x(87)90001-1. [DOI] [PubMed] [Google Scholar]
  22. Göttlinger H. G., Dorfman T., Sodroski J. G., Haseltine W. A. Effect of mutations affecting the p6 gag protein on human immunodeficiency virus particle release. Proc Natl Acad Sci U S A. 1991 Apr 15;88(8):3195–3199. doi: 10.1073/pnas.88.8.3195. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Göttlinger H. G., Sodroski J. G., Haseltine W. A. Role of capsid precursor processing and myristoylation in morphogenesis and infectivity of human immunodeficiency virus type 1. Proc Natl Acad Sci U S A. 1989 Aug;86(15):5781–5785. doi: 10.1073/pnas.86.15.5781. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Hansen L. J., Chalker D. L., Sandmeyer S. B. Ty3, a yeast retrotransposon associated with tRNA genes, has homology to animal retroviruses. Mol Cell Biol. 1988 Dec;8(12):5245–5256. doi: 10.1128/mcb.8.12.5245. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Hsu H. W., Schwartzberg P., Goff S. P. Point mutations in the P30 domain of the gag gene of Moloney murine leukemia virus. Virology. 1985 Apr 15;142(1):211–214. doi: 10.1016/0042-6822(85)90435-0. [DOI] [PubMed] [Google Scholar]
  26. Hunter E. Biological techniques for avian sarcoma viruses. Methods Enzymol. 1979;58:379–393. doi: 10.1016/s0076-6879(79)58153-1. [DOI] [PubMed] [Google Scholar]
  27. Kunkel T. A., Roberts J. D., Zakour R. A. Rapid and efficient site-specific mutagenesis without phenotypic selection. Methods Enzymol. 1987;154:367–382. doi: 10.1016/0076-6879(87)54085-x. [DOI] [PubMed] [Google Scholar]
  28. Laprevotte I., Hampe A., Sherr C. J., Galibert F. Nucleotide sequence of the gag gene and gag-pol junction of feline leukemia virus. J Virol. 1984 Jun;50(3):884–894. doi: 10.1128/jvi.50.3.884-894.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Leis J., Baltimore D., Bishop J. M., Coffin J., Fleissner E., Goff S. P., Oroszlan S., Robinson H., Skalka A. M., Temin H. M. Standardized and simplified nomenclature for proteins common to all retroviruses. J Virol. 1988 May;62(5):1808–1809. doi: 10.1128/jvi.62.5.1808-1809.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Malik K. T., Even J., Karpas A. Molecular cloning and complete nucleotide sequence of an adult T cell leukaemia virus/human T cell leukaemia virus type I (ATLV/HTLV-I) isolate of Caribbean origin: relationship to other members of the ATLV/HTLV-I subgroup. J Gen Virol. 1988 Jul;69(Pt 7):1695–1710. doi: 10.1099/0022-1317-69-7-1695. [DOI] [PubMed] [Google Scholar]
  31. Mammano F., Ohagen A., Höglund S., Göttlinger H. G. Role of the major homology region of human immunodeficiency virus type 1 in virion morphogenesis. J Virol. 1994 Aug;68(8):4927–4936. doi: 10.1128/jvi.68.8.4927-4936.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Maurer B., Bannert H., Darai G., Flügel R. M. Analysis of the primary structure of the long terminal repeat and the gag and pol genes of the human spumaretrovirus. J Virol. 1988 May;62(5):1590–1597. doi: 10.1128/jvi.62.5.1590-1597.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Mervis R. J., Ahmad N., Lillehoj E. P., Raum M. G., Salazar F. H., Chan H. W., Venkatesan S. The gag gene products of human immunodeficiency virus type 1: alignment within the gag open reading frame, identification of posttranslational modifications, and evidence for alternative gag precursors. J Virol. 1988 Nov;62(11):3993–4002. doi: 10.1128/jvi.62.11.3993-4002.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Moore R., Dixon M., Smith R., Peters G., Dickson C. Complete nucleotide sequence of a milk-transmitted mouse mammary tumor virus: two frameshift suppression events are required for translation of gag and pol. J Virol. 1987 Feb;61(2):480–490. doi: 10.1128/jvi.61.2.480-490.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Moscovici C., Moscovici M. G., Jimenez H., Lai M. M., Hayman M. J., Vogt P. K. Continuous tissue culture cell lines derived from chemically induced tumors of Japanese quail. Cell. 1977 May;11(1):95–103. doi: 10.1016/0092-8674(77)90320-8. [DOI] [PubMed] [Google Scholar]
  36. Nermut M. V., Frank H., Schäfer W. Properties of mouse leukemia viruses. 3. Electron microscopic appearance as revealed after conventional preparation techniques as well as freeze-drying and freeze-etching. Virology. 1972 Aug;49(2):345–358. doi: 10.1016/0042-6822(72)90487-4. [DOI] [PubMed] [Google Scholar]
  37. Nermut M. V., Grief C., Hashmi S., Hockley D. J. Further evidence of icosahedral symmetry in human and simian immunodeficiency virus. AIDS Res Hum Retroviruses. 1993 Oct;9(10):929–938. doi: 10.1089/aid.1993.9.929. [DOI] [PubMed] [Google Scholar]
  38. Novak U., Friedrich R., Moelling K. Elongation of DNA complementary to the 5' end of the avian sarcoma virus genome by the virion-associated RNA-dependent DNA polymerase. J Virol. 1979 May;30(2):438–452. doi: 10.1128/jvi.30.2.438-452.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Patarca R., Haseltine W. A. A major retroviral core protein related to EPA and TIMP. 1985 Nov 28-Dec 4Nature. 318(6044):390–390. doi: 10.1038/318390a0. [DOI] [PubMed] [Google Scholar]
  40. Pepinsky R. B., Cappiello D., Wilkowski C., Vogt V. M. Chemical crosslinking of proteins in avian sarcoma and leukemia viruses. Virology. 1980 Apr 15;102(1):205–210. doi: 10.1016/0042-6822(80)90081-1. [DOI] [PubMed] [Google Scholar]
  41. Perry S. T., Flaherty M. T., Kelley M. J., Clabough D. L., Tronick S. R., Coggins L., Whetter L., Lengel C. R., Fuller F. The surface envelope protein gene region of equine infectious anemia virus is not an important determinant of tropism in vitro. J Virol. 1992 Jul;66(7):4085–4097. doi: 10.1128/jvi.66.7.4085-4097.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Petropoulos C. J., Hughes S. H. Replication-competent retrovirus vectors for the transfer and expression of gene cassettes in avian cells. J Virol. 1991 Jul;65(7):3728–3737. doi: 10.1128/jvi.65.7.3728-3737.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Pryciak P. M., Varmus H. E. Fv-1 restriction and its effects on murine leukemia virus integration in vivo and in vitro. J Virol. 1992 Oct;66(10):5959–5966. doi: 10.1128/jvi.66.10.5959-5966.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Reddy E. P., Reynolds R. K., Watson D. K., Schultz R. A., Lautenberger J., Papas T. S. Nucleotide sequence analysis of the proviral genome of avian myelocytomatosis virus (MC29). Proc Natl Acad Sci U S A. 1983 May;80(9):2500–2504. doi: 10.1073/pnas.80.9.2500. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Renne R., Friedl E., Schweizer M., Fleps U., Turek R., Neumann-Haefelin D. Genomic organization and expression of simian foamy virus type 3 (SFV-3). Virology. 1992 Feb;186(2):597–608. doi: 10.1016/0042-6822(92)90026-l. [DOI] [PubMed] [Google Scholar]
  46. Sagata N., Yasunaga T., Tsuzuku-Kawamura J., Ohishi K., Ogawa Y., Ikawa Y. Complete nucleotide sequence of the genome of bovine leukemia virus: its evolutionary relationship to other retroviruses. Proc Natl Acad Sci U S A. 1985 Feb;82(3):677–681. doi: 10.1073/pnas.82.3.677. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Sakalian M., Wills J. W., Vogt V. M. Efficiency and selectivity of RNA packaging by Rous sarcoma virus Gag deletion mutants. J Virol. 1994 Sep;68(9):5969–5981. doi: 10.1128/jvi.68.9.5969-5981.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Saltarelli M., Querat G., Konings D. A., Vigne R., Clements J. E. Nucleotide sequence and transcriptional analysis of molecular clones of CAEV which generate infectious virus. Virology. 1990 Nov;179(1):347–364. doi: 10.1016/0042-6822(90)90303-9. [DOI] [PubMed] [Google Scholar]
  49. Schwartz D. E., Tizard R., Gilbert W. Nucleotide sequence of Rous sarcoma virus. Cell. 1983 Mar;32(3):853–869. doi: 10.1016/0092-8674(83)90071-5. [DOI] [PubMed] [Google Scholar]
  50. Shimotohno K., Takahashi Y., Shimizu N., Gojobori T., Golde D. W., Chen I. S., Miwa M., Sugimura T. Complete nucleotide sequence of an infectious clone of human T-cell leukemia virus type II: an open reading frame for the protease gene. Proc Natl Acad Sci U S A. 1985 May;82(10):3101–3105. doi: 10.1073/pnas.82.10.3101. [DOI] [PMC free article] [PubMed] [Google Scholar]
  51. Shinnick T. M., Lerner R. A., Sutcliffe J. G. Nucleotide sequence of Moloney murine leukaemia virus. Nature. 1981 Oct 15;293(5833):543–548. doi: 10.1038/293543a0. [DOI] [PubMed] [Google Scholar]
  52. Sonigo P., Alizon M., Staskus K., Klatzmann D., Cole S., Danos O., Retzel E., Tiollais P., Haase A., Wain-Hobson S. Nucleotide sequence of the visna lentivirus: relationship to the AIDS virus. Cell. 1985 Aug;42(1):369–382. doi: 10.1016/s0092-8674(85)80132-x. [DOI] [PubMed] [Google Scholar]
  53. Sonigo P., Barker C., Hunter E., Wain-Hobson S. Nucleotide sequence of Mason-Pfizer monkey virus: an immunosuppressive D-type retrovirus. Cell. 1986 May 9;45(3):375–385. doi: 10.1016/0092-8674(86)90323-5. [DOI] [PubMed] [Google Scholar]
  54. Steven A. C., Greenstone H. L., Booy F. P., Black L. W., Ross P. D. Conformational changes of a viral capsid protein. Thermodynamic rationale for proteolytic regulation of bacteriophage T4 capsid expansion, co-operativity, and super-stabilization by soc binding. J Mol Biol. 1992 Dec 5;228(3):870–884. doi: 10.1016/0022-2836(92)90871-g. [DOI] [PubMed] [Google Scholar]
  55. Strambio-de-Castillia C., Hunter E. Mutational analysis of the major homology region of Mason-Pfizer monkey virus by use of saturation mutagenesis. J Virol. 1992 Dec;66(12):7021–7032. doi: 10.1128/jvi.66.12.7021-7032.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  56. Stromberg K., Hurley N. E., Davis N. L., Rueckert R. R., Fleissner E. Structural studies of avian myeloblastosis virus: comparison of polypeptides in virion and core component by dodecyl sulfate-polyacrylamide gel electrophoresis. J Virol. 1974 Feb;13(2):513–528. doi: 10.1128/jvi.13.2.513-528.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  57. Talbott R. L., Sparger E. E., Lovelace K. M., Fitch W. M., Pedersen N. C., Luciw P. A., Elder J. H. Nucleotide sequence and genomic organization of feline immunodeficiency virus. Proc Natl Acad Sci U S A. 1989 Aug;86(15):5743–5747. doi: 10.1073/pnas.86.15.5743. [DOI] [PMC free article] [PubMed] [Google Scholar]
  58. Tamura T. A. Provirus of M7 baboon endogenous virus: nucleotide sequence of the gag-pol region. J Virol. 1983 Jul;47(1):137–145. doi: 10.1128/jvi.47.1.137-145.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Tritch R. J., Cheng Y. E., Yin F. H., Erickson-Viitanen S. Mutagenesis of protease cleavage sites in the human immunodeficiency virus type 1 gag polyprotein. J Virol. 1991 Feb;65(2):922–930. doi: 10.1128/jvi.65.2.922-930.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  60. Wagner R., Deml L., Fliessbach H., Wanner G., Wolf H. Assembly and extracellular release of chimeric HIV-1 Pr55gag retrovirus-like particles. Virology. 1994 Apr;200(1):162–175. doi: 10.1006/viro.1994.1175. [DOI] [PubMed] [Google Scholar]
  61. Wang C. T., Barklis E. Assembly, processing, and infectivity of human immunodeficiency virus type 1 gag mutants. J Virol. 1993 Jul;67(7):4264–4273. doi: 10.1128/jvi.67.7.4264-4273.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  62. Warmington J. R., Waring R. B., Newlon C. S., Indge K. J., Oliver S. G. Nucleotide sequence characterization of Ty 1-17, a class II transposon from yeast. Nucleic Acids Res. 1985 Sep 25;13(18):6679–6693. doi: 10.1093/nar/13.18.6679. [DOI] [PMC free article] [PubMed] [Google Scholar]
  63. Weldon R. A., Jr, Erdie C. R., Oliver M. G., Wills J. W. Incorporation of chimeric gag protein into retroviral particles. J Virol. 1990 Sep;64(9):4169–4179. doi: 10.1128/jvi.64.9.4169-4179.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  64. Weldon R. A., Jr, Wills J. W. Characterization of a small (25-kilodalton) derivative of the Rous sarcoma virus Gag protein competent for particle release. J Virol. 1993 Sep;67(9):5550–5561. doi: 10.1128/jvi.67.9.5550-5561.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  65. Wills J. W., Cameron C. E., Wilson C. B., Xiang Y., Bennett R. P., Leis J. An assembly domain of the Rous sarcoma virus Gag protein required late in budding. J Virol. 1994 Oct;68(10):6605–6618. doi: 10.1128/jvi.68.10.6605-6618.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  66. Wills J. W., Craven R. C., Achacoso J. A. Creation and expression of myristylated forms of Rous sarcoma virus gag protein in mammalian cells. J Virol. 1989 Oct;63(10):4331–4343. doi: 10.1128/jvi.63.10.4331-4343.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  67. Wills J. W., Craven R. C. Form, function, and use of retroviral gag proteins. AIDS. 1991 Jun;5(6):639–654. doi: 10.1097/00002030-199106000-00002. [DOI] [PubMed] [Google Scholar]
  68. Wills J. W., Craven R. C., Weldon R. A., Jr, Nelle T. D., Erdie C. R. Suppression of retroviral MA deletions by the amino-terminal membrane-binding domain of p60src. J Virol. 1991 Jul;65(7):3804–3812. doi: 10.1128/jvi.65.7.3804-3812.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  69. York D. F., Vigne R., Verwoerd D. W., Querat G. Nucleotide sequence of the jaagsiekte retrovirus, an exogenous and endogenous type D and B retrovirus of sheep and goats. J Virol. 1992 Aug;66(8):4930–4939. doi: 10.1128/jvi.66.8.4930-4939.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  70. Zhoa Y., Jones I. M., Hockley D. J., Nermut M. V., Roy P. Complementation of human immunodeficiency virus (HIV-1) gag particle formation. Virology. 1994 Mar;199(2):403–408. doi: 10.1006/viro.1994.1138. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Virology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES