Functional cross-talk between distant domains of Chikungunya virus non-structural protein 2 is decisive for its RNA-modulating activity
Autor(es): Das Pratyush Kumar, Merits Andres, Lulla Aleksei
Resumo: Chikungunya virus (CHIKV) non-structural protein 2 (nsP2) is a multifunctional protein that is considered a master regulator of the viral life cycle - a main viral factor responsible for cytopathic effects - subversion of antiviral defense. The C-terminal part of nsP2 possesses protease activity, whereas the N-terminal part exhibits NTPase - RNA triphosphatase activity - is proposed to have helicase activity. Bioinformatics analysis classified CHIKV nsP2 into helicase superfamily 1. However, the biochemical significance of a coexistence of two functionally unrelated modules in this single protein remains unknown. In this study, recombinant nsP2 demonstrated unwinding of double-str-ed RNA in a 5'-3' directionally biased manner - RNA str- annealing activity. Comparative analysis of NTPase - helicase activities of wild type nsP2 with enzymatic capabilities of different truncated or N-terminally extended variants of nsP2 revealed that the C-terminal part of the protein is indispensable for helicase functionality - presumably provides a platform for RNA binding, whereas the N-terminal-most region is apparently involved in obtaining a conformation of nsP2 that allows for its maximal enzymatic activities. The establishment of the protocols for the production of biochemically active CHIKV nsP2 - optimization of the parameters for helicase - NTPase assays are expected to provide the starting point for a further search of possibilities for therapeutic interventions to suppress alphaviral infections.
Palavras-Chave: Alphavirus; Chikungunya Virus; Enzymes; NTPase; Positive-strand RNA Viruses; Protein Purification; RNA Annealing; RNA Helicase; SF1 Helicase; Viral Replication
Imprenta: The Journal of Biological Chemistry, v. 289, n. 9, p. 5635-5653, 2014
Identificador do objeto digital: 10.1074/jbc.M113.503433
Descritores: Chikungunya virus - Biosynthesis ; Chikungunya virus - Molecular structure ; Chikungunya virus - Pathogenesis ; Chikungunya virus - Proteins ; Chikungunya virus - RNA ; Chikungunya virus - Viral infections ; Chikungunya Virus - Virus ; Chikungunya virus - Chikungunya fever
Data de publicação: 2014
