Volume 33, No 7, Jul 2023
EISSN: 1748-7838 2018
impact factor 17.848*
(Clarivate Analytics, 2019)
Volume 33 Issue 7, July 2023: 565-568
Structure of the SNAPc-bound RNA polymerase III preinitiation complex
Haifeng Hou1,? , Qianwei Jin1,? , Yulei Ren1,? , Zhenguo Chen1 , Qianmin Wang1,* , Yanhui Xu1,2,3,*1Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, China
Eukaryotic RNA polymerase III (Pol III) is required for transcribing a large amount of short non-coding RNAs, including tRNAs, 5S rRNA, and U6 snRNA.1 These products play essential roles in a large variety of cellular processes, such as translation, RNA processing, and transcription regulations. Different types of Pol III-specific genes are recognized by different multi-subunit transcription factors during the early stage of the transcription initiation, and Pol III is subsequently recruited to assemble the preinitiation complex (PIC). As a prototype of the Pol III-transcribing gene, the U6 snRNA gene contains a TATA box and a proximal sequence element (PSE), which are recognized by TFIIIB (TBP–BRF2–BDP1) and the small nuclear RNA-activating protein complex (SNAPc), respectively2 (Supplementary information, Note S1). Previous biochemical studies have identified domains or regions of SNAPc required for PSE recognition.3 Despite extensive studies of the Pol III elongation complex and yeast Pol III PIC assembly, it remains incompletely understood how SNAPc-containing Pol III PIC is organized on the U6 promoter and how the promoter DNA is melted within the PIC complex.