Table 3:

A summary of the structures and functions of the alphaviral nsPs

Protein	Structures	Functions
nsP1	methyl transferase domain, guanyl transferase domain, membrane association domains	caps viral RNA making it usable by ribosomes, anchors the replication machinery to cellular membranes^{111,129–131,133–136}
nsP2	helicase domain, ADP binding region, cysteine protease, methyl transferase like domain	unwinds viral RNA for replication, cleaves the polyprotein into its constitutive parts, digests host cell proteins^{77,132,138–142,144–146,152–157}
nsP3	macrodomain, alphavirus unique domain, hypervariable domain	poorly described, necessary for replication, highly involved in host cell interactions^{129,160–168,170–172,174,175}
nsP4	RNA dependent RNA polymerase domain	synthesizes new viral RNA^{71,77,129,176–178,180–182,185}