A recent study by Chinese scientists has successfully revealed the mystery of the fourth RNA polymerase in higher plants. On the 24th, the international authoritative journal "Science" magazine published relevant research papers.
3D structure of RNA polymerase IV (Pol IV) and RDR2 protein complexes (courtesy of respondent)
In plant cells, the role of RNA polymerase is to transcribe genetic information carried by genomic DNA onto RNA molecules. In the evolution of life, higher plants formed a total of five RNA polymerases. Among them, the three-dimensional structure and working mechanism of three RNA polymerases have been analyzed one after another, and they can complete the "transcription" task alone.
Previous studies have found that the fourth RNA polymerase in higher plants must be supported by a protein machine called "RDR2" to complete the "transcription" task. What is the internal structure between RNA polymerase IV and "little partner" RDR2, and how does it work together? Scientists have been unclear.
The two research teams of Zhang Yu and Wang Jiawei of the Center for Excellence in Molecular plant sciences of the Chinese Academy of Sciences and the team of Feng Yu of Zhejiang University collaborated to innovatively develop a protein isolation and purification method based on plant suspension cells, successfully analyzed the three-dimensional structure of RNA polymerase IV and "small partner" RDR2 protein complex, and proposed a unique molecular mechanism for synthesizing double-stranded RNA with double-stranded DNA as a template.
The study found that the collaboration between RNA polymerase IV and the "little partner" RDR2 was very clever, and the two sides had an internal "secret channel". RNA polymerase IV uses double-stranded DNA as a template to synthesize single-stranded RNA and transmit it to "small partner" RDR2 through an internal "secret channel"; "small partner" RDR2 directly uses single-stranded RNA as a template to synthesize double-stranded RNA. Working together, the "two" can synthesize double-stranded RNA continuously and efficiently, helping plant cells successfully complete their next steps.
On the 23rd, Zhang Yu, a researcher at the Center for Excellence in Molecular Plant Science of the Chinese Academy of Sciences, introduced the scientific research results at a press conference. Photo by Xinhua News Agency reporter Zhang Jiansong
Industry experts believe that this latest study successfully analyzed the structure of the fourth RNA polymerase in higher plants, revealed the unique structure and collaborative mechanism of the double RNA polymerase complex, proposed a new working mode of the transcriptional protein machine, and is a major breakthrough in the frontier field of molecular biology and plant science.
At present, two research teams, Zhang Yu and Wang Jiawei of the Center for Excellence in Molecular Plant Science of the Chinese Academy of Sciences, are working on the analysis of the fifth RNA polymerase of higher plants. (Reporter Zhang Jiansong)