Post by Nadica (She/Her) on Jul 14, 2024 23:13:57 GMT
Liquid–liquid phase separation by SARS-CoV-2 nucleocapsid protein and RNA - Published Sept 8, 2020
Dear Editor,
The COVID-19 pandemic worldwide is caused by a novel coronavirus SARS-CoV-2 (the severe acute respiratory syndrome coronavirus 2).1 After viral invasion into the host cells, the ~30 kb viral genome RNA injected is translated into structural and non-structural proteins to replicate viral genome and assemble more viral particles. Many copies of nucleocapsid (N) protein can bind to viral genome RNA and pack it into ~100 nm particles, assisting membrane (M) and envelope (E) proteins to efficiently assemble the viral envelope.2 The exact molecular mechanism by which N protein packs up the viral genome still remains elusive.
An N protein of SARS-CoV-2 consists of an N-terminal RNA-binding domain (NTD) and a C-terminal dimerization domain (CTD) and shares ~90% sequence identity with N protein of SARS-CoV (Supplementary information, Fig. S1a). The regions located between the N-terminus and NTD, between NTD and CTD, and between CTD and the C-terminus of the N protein of SARS-CoV-2 (thereafter referred to as N protein) are predicted to be intrinsically disordered (Supplementary information, Fig. S1b, c). At neutral pH, the N protein is positively charged (+24 e), consistent with its strong binding affinity with negatively charged RNA, and this has also been validated by the nucleotide contaminant in N protein purification (Supplementary information, Fig. S2a, b). The gel filtration and dynamic light scattering results further suggested the oligmerization of N protein (Supplementary information, Fig. S2c–f). Altogether, the sequence and structure features of N protein are similar to those of other proteins that have been reported to undergo liquid–liquid phase separation (LLPS) with nucleic acids.3 Thus, we hypothesized that N protein may also undergo LLPS with viral genome RNA and potentially facilitate viral assembly.
(Read the whole article via the link above.)
Dear Editor,
The COVID-19 pandemic worldwide is caused by a novel coronavirus SARS-CoV-2 (the severe acute respiratory syndrome coronavirus 2).1 After viral invasion into the host cells, the ~30 kb viral genome RNA injected is translated into structural and non-structural proteins to replicate viral genome and assemble more viral particles. Many copies of nucleocapsid (N) protein can bind to viral genome RNA and pack it into ~100 nm particles, assisting membrane (M) and envelope (E) proteins to efficiently assemble the viral envelope.2 The exact molecular mechanism by which N protein packs up the viral genome still remains elusive.
An N protein of SARS-CoV-2 consists of an N-terminal RNA-binding domain (NTD) and a C-terminal dimerization domain (CTD) and shares ~90% sequence identity with N protein of SARS-CoV (Supplementary information, Fig. S1a). The regions located between the N-terminus and NTD, between NTD and CTD, and between CTD and the C-terminus of the N protein of SARS-CoV-2 (thereafter referred to as N protein) are predicted to be intrinsically disordered (Supplementary information, Fig. S1b, c). At neutral pH, the N protein is positively charged (+24 e), consistent with its strong binding affinity with negatively charged RNA, and this has also been validated by the nucleotide contaminant in N protein purification (Supplementary information, Fig. S2a, b). The gel filtration and dynamic light scattering results further suggested the oligmerization of N protein (Supplementary information, Fig. S2c–f). Altogether, the sequence and structure features of N protein are similar to those of other proteins that have been reported to undergo liquid–liquid phase separation (LLPS) with nucleic acids.3 Thus, we hypothesized that N protein may also undergo LLPS with viral genome RNA and potentially facilitate viral assembly.
(Read the whole article via the link above.)