During severe acute respiratory syndrome coronavirus(SARS-CoV)infection,the activity of the replication/transcription complexes(RTC)quickly peaks at 6 hours post infection(h.p.i)and then diminishes significantly in th...During severe acute respiratory syndrome coronavirus(SARS-CoV)infection,the activity of the replication/transcription complexes(RTC)quickly peaks at 6 hours post infection(h.p.i)and then diminishes significantly in the late post-infection stages.This“down-up-down”regulation of RNA synthesis distinguishes different viral stages:primary translation,genome replication,and finally viron assembly.Regarding the nsp8 as the primase in RNA synthesis,we confirmed that the proteolysis product of the primase(nsp8)contains the globular domain(nsp8C),and indentified the resectioning site that is notably conserved in all the three groups of coronavirus.We subsequently crystallized the complex of SARS-CoV nsp8C and nsp7,and the 3-D structure of this domain revealed its capability to interfuse into the hexadecamer super-complex.This specific proteolysis may indicate one possible mechanism by which coronaviruses to switch from viral infection to genome replication and viral assembly stages.展开更多
基金This work was supported by Project 973 of the Ministry of Science and Technology of China(Nos.2006CB806503,2007CB914301)the National Natural Science Foundation of China(Grant Nos.30221003,30730022).
文摘During severe acute respiratory syndrome coronavirus(SARS-CoV)infection,the activity of the replication/transcription complexes(RTC)quickly peaks at 6 hours post infection(h.p.i)and then diminishes significantly in the late post-infection stages.This“down-up-down”regulation of RNA synthesis distinguishes different viral stages:primary translation,genome replication,and finally viron assembly.Regarding the nsp8 as the primase in RNA synthesis,we confirmed that the proteolysis product of the primase(nsp8)contains the globular domain(nsp8C),and indentified the resectioning site that is notably conserved in all the three groups of coronavirus.We subsequently crystallized the complex of SARS-CoV nsp8C and nsp7,and the 3-D structure of this domain revealed its capability to interfuse into the hexadecamer super-complex.This specific proteolysis may indicate one possible mechanism by which coronaviruses to switch from viral infection to genome replication and viral assembly stages.
