Structural highlights
Function
A0A385H8D7_9ALPC Nsp7-nsp8 hexadecamer may possibly confer processivity to the polymerase, maybe by binding to dsRNA or by producing primers utilized by the latter.[ARBA:ARBA00002928] Nsp9 is a ssRNA-binding protein.[ARBA:ARBA00003140] The exoribonuclease acts on both ssRNA and dsRNA in a 3' to 5' direction.[ARBA:ARBA00003315] The papain-like proteinase 1 (PLP1) and papain-like proteinase 2 (PLP2) are responsible for the cleavages located at the N-terminus of the replicase polyprotein. In addition, PLP2 possesses a deubiquitinating/deISGylating activity and processes both 'Lys-48'- and 'Lys-63'-linked polyubiquitin chains from cellular substrates. PLP2 also antagonizes innate immune induction of type I interferon by blocking the nuclear translocation of host IRF-3.[ARBA:ARBA00025562] The replicase polyprotein of coronaviruses is a multifunctional protein: it contains the activities necessary for the transcription of negative stranded RNA, leader RNA, subgenomic mRNAs and progeny virion RNA as well as proteinases responsible for the cleavage of the polyprotein into functional products.[ARBA:ARBA00003368]
