Ancient protein protects bacteria from modern viral pathogens

Researchers have resurrected a 2.5 billion-year-old protein, engineered its gene sequence into modern Escherichia coli, and observed that the modified bacteria could avoid harm from invading viruses.

The protein hails from the Precambrian era and is the ancient form of thioredoxin, which plays an important role in all organisms studied to date: It shuttles electrons around a cell so that chemical reactions can occur. Both then and now, the bacteriophage T7 virus successfully infects host E. coli by hijacking the bacterium’s thioredoxin. Although the overall architecture of ancient and modern thioredoxin is the same, the proteins’ amino acid sequences are only about 70% similar. The 30% difference is big enough to protect ancient thioredoxin engineered into E. coli (J. Cell Rep. 2017, DOI: 10.1016/j.celrep.2017.04.037).

The research team, led by Jose M. Sanchez-Ruiz at the University of Granada, argues that the strategy of inserting genes for ancient proteins into modern organisms could be useful in both synthetic biology and crop protection. For example, agricultural plants could be engineered to produce ancient proteins so that pathogens cannot hijack the crops, and thereby our food supply.