New research unveils cellular RNA synthesis mechanism

Scientists in Shanghai have decoded the mysterious cellular mechanism that synthesizes double-stranded RNA in plants, marking a major breakthrough on the frontier of studies in molecular biology.

The research, led by the Center of Excellence in Molecular Plant Sciences at the Chinese Academy of Science (CEMPS), determined the three-dimensional structures of a two-polymerase complex that produces double-stranded RNA.

It revealed how DNA–dependent RNA polymerases – Pol IV and RDR2 – are assembled into a tight two–RNA–polymerase complex and efficiently produce double-stranded RNA using genomic double-stranded DNA as the template.

Pol IV and RDR2 smartly build an inter-polymerase channel, through which the Pol IV-generated transcript is handed over to the RDR2 active site after being backtracked, where it is used as the template for double-stranded RNA (dsRNA) synthesis.

The research was led by Zhang Yu and Wang Jiawei from CEMPS with collaboration from Feng Yu at Zhejiang University. It has been published in the top scientific journal "Science."