Point Mutations in the Proximal Cys-His Box of Rous Sarcoma Virus Nucleocapsid Protein

Article Article scientifique Article Point Mutations in the Proximal Cys-His Box of Rous Sarcoma Virus Nucleocapsid Protein eng 1990 author Dupraz Philippe 888119 author Oertle Suzanne 24574 author Meric Claude 68095 author Damay Pascal 23228 author Spahr Pierre-François 25043 4978-4987 10.1128/JVI.64.10.4978-4987.1990 2168981 0022-538X To extend our previous studies of the function of the Cys-His box of Rous sarcoma virus NC protein, we have constructed a series of point mutations of the conserved or nonconserved amino acids of the proximal Cys-His box and a one-amino-acid deletion. All mutants were characterized for production of viral proteins and particles, for packaging and maturation of viral RNA, for reverse transcriptase activity, and for infectivity. Our results indicated the following. (i) Mutations affecting the strictly conserved amino acids cysteine 21, cysteine 24, and histidine 29 were lethal; only the mutant His-29→Pro was still able to package viral RNA, most of it in an immature form. (ii) Mutation of the highly conserved glycine 28 to valine reduced viral RNA packaging by 90% and infectivity 30-fold, whereas mutant Gly-28→Ala was fully infectious. This suggests a steric hindrance limit at this position. (iii) Shortening the distance between cysteine 24 and histidine 29 by deleting one amino acid abolished the maturation of viral RNA and yielded noninfectious particles. (iv) Substitution of tyrosine 22 by serine lowered viral RNA packaging efficiency and yielded particles that were 400-fold less infectious; double mutant Tyr-22Thr-23→SerSer had the same infectivity as Tyr-22→Ser, whereas mutant Thr-23→Ser was fully infectious. (v) Changing glutamine 33 to a charged glutamate residue did not affect virus infectivity. Similarities and differences between our avian mutants and those in murine retroviruses are discussed. Amino Acid Sequence Animals Avian Sarcoma Viruses/genetics Capsid/genetics Cells Cultured Chick Embryo Cysteine Gene Products gag/genetics Viral genes Histidine Molecular Sequence Data Mutation Oligonucleotide Probes Viral RNA/genetics/isolation & purification Transfection Viral Core Proteins/genetics Viral Proteins/genetics/isolation & purification Virion/genetics Dewey 570 Swiss National Science Foundation 3.066.087 CH 43 Département de biologie moléculaire 161 false Journal of Virology 64 10 aae17ea1-7215-4ddc-933a-85f2ee0d874f Article (Published version) Restricted JV-1990-Dupraz-4978.full.pdf 3041873 application/pdf restrictedAccess Faculté des sciences / Section de biologie / Département de biologie moléculaire

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Point Mutations in the Proximal Cys-His Box of Rous Sarcoma Virus Nucleocapsid Protein	Journal of Virology			1990	266	0

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Dupraz, Philippe