Coronavirus nucleocapsid protein is an RNA chaperone.
RNA chaperones are nonspecific nucleic acid binding proteins with long disordered regions that help RNA molecules to adopt its functional conformation. Coronavirus nucleoproteins (N) are nonspecific RNA-binding proteins with long disordered regions. Therefore, we investigated whether transmissible gastroenteritis coronavirus (TGEV) N protein was an RNA chaperone. Purified N protein enhanced hammerhead ribozyme self-cleavage and nucleic acids annealing, which are properties that define RNA chaperones. In contrast, another RNA-binding protein, PTB, did not show these activities. N protein chaperone activity was blocked by specific monoclonal antibodies. Therefore, it was concluded that TGEV N protein is an RNA chaperone. In addition, we have shown that purified severe acute respiratory syndrome (SARS)-CoV N protein also has RNA chaperone activity. In silico predictions of disordered domains showed a similar pattern for all coronavirus N proteins evaluated. Altogether, these data led us to suggest that all coronavirus N proteins might be RNA chaperones.
Zúñiga
Sonia
S
Centro Nacional de Biotecnología, CSIC, Department of Molecular and Cell Biology, Campus Universidad Autónoma, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
Sola
Isabel
I
Moreno
Jose L
JL
Sabella
Patricia
P
Plana-Durán
Juan
J
Enjuanes
Luis
L
D018833:Chaperonins / Q000737:chemistry / Q000378:metabolism; D017934:Coronavirus / Q000737:chemistry*; D000086462:Coronavirus Nucleocapsid Proteins; D016679:Genome, Viral / Q000502:physiology; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D019590:Nucleocapsid Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016337:RNA, Catalytic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism*; D014779:Virus Replication / Q000502:physiology*
D000086462:Coronavirus Nucleocapsid Proteins; D018832:Molecular Chaperones; D019590:Nucleocapsid Proteins; D016337:RNA, Catalytic; D012367:RNA, Viral; D018833:Chaperonins