Coronavirus nucleocapsid protein facilitates template switching and is required for efficient transcription.
Purified nucleocapsid protein (N protein) from transmissible gastroenteritis virus (TGEV) enhanced hammerhead ribozyme self-cleavage and favored nucleic acid annealing, properties that define RNA chaperones, as previously reported. Several TGEV N-protein deletion mutants were expressed in Escherichia coli and purified, and their RNA binding ability and RNA chaperone activity were evaluated. The smallest N-protein domain analyzed with RNA chaperone activity, facilitating DNA and RNA annealing, contained the central unstructured region (amino acids 117 to 268). Interestingly, N protein and its deletion mutants with RNA chaperone activity enhanced template switching in a retrovirus-derived heterologous system, reinforcing the concept that TGEV N protein is an RNA chaperone that could be involved in template switching. This result is in agreement with the observation that in vivo, N protein is not necessary for TGEV replication, but it is required for efficient transcription.
Zúñiga
Sonia
S
Department of Molecular and Cell Biology, Centro Nacional de Biotecnología, CSIC, Darwin, 3, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.
Cruz
Jazmina L G
JL
Sola
Isabel
I
Mateos-Gómez
Pedro A
PA
Palacio
Lorena
L
Enjuanes
Luis
L
D000818:Animals; D000086462:Coronavirus Nucleocapsid Proteins; D005814:Genes, Viral; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D019590:Nucleocapsid Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D017434:Protein Structure, Tertiary; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D013698:Templates, Genetic; D014158:Transcription, Genetic; D005760:Transmissible gastroenteritis virus / Q000235:genetics* / Q000502:physiology*; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
D000086462:Coronavirus Nucleocapsid Proteins; D018832:Molecular Chaperones; D019590:Nucleocapsid Proteins; D012367:RNA, Viral; D011994:Recombinant Proteins