Viruses have limited genetic material-;and few proteins-;so all the pieces must work extra hard. Zika is a great example; the virus only produces 10 proteins. Now, in a study published in the journal PLOS Pathogens, researchers at Sanford Burnham Prebys have shown how the virus does so much with so little and may have identified a therapeutic vulnerability.
In the study, the research team showed that Zika’s enzyme-;NS2B-NS3-;is a multipurpose tool with two essential functions: breaking up proteins (a protease) and dividing its own double-stranded RNA into single strands (a helicase).
We found that Zika’s enzyme complex changes function based on how it’s shaped. When in the closed conformation, it acts as a classic protease. But then it cycles between open and super-open conformations, which allows it to grab and then release a single strand of RNA-;and these functions are essential for viral replication.”
Alexey Terskikh, Ph.D., associate professor at Sanford Burnham Prebys and senior author of the paper
Zika is an RNA virus that’s part of a family of deadly pathogens called flaviviruses, which include West Nile, dengue fever, yellow fever, Japanese encephalitis and others. The virus is transmitted by mosquitoes and infects uterine and placental cells (among other cell types), making it particularly dangerous for pregnant women. Once inside host cells, the virus re-engineers them to produce more Zika.
Understanding Zika on the molecular level could have an enormous payoff: a therapeutic target. It would be difficult to create safe drugs that target the