Chun Yang, Pratik Basnet, Samah Sharmin, Hui Shen, Craig D Kaplan, Kenji Murakami
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引用次数: 0
Abstract
RNA polymerase II (pol II) initiates transcription from transcription start sites (TSSs) located ∼30–35 bp downstream of the TATA box in metazoans, whereas in the yeast Saccharomyces cerevisiae, pol II scans further downstream TSSs located ∼40–120 bp downstream of the TATA box. Previously, we found that removal of the kinase module TFIIK (Kin28–Ccl1–Tfb3) from TFIIH shifts the TSS in a yeast in vitro system upstream to the location observed in metazoans and that addition of recombinant Tfb3 back to TFIIH-ΔTFIIK restores the downstream TSS usage. Here, we report that this biochemical activity of yeast TFIIK in TSS scanning is attributable to the Tfb3 RING domain at the interface with pol II in the pre-initiation complex (PIC): especially, swapping Tfb3 Pro51—a residue conserved among all fungi—with Ala or Ser as in MAT1, the metazoan homolog of Tfb3, confers an upstream TSS shift in vitro in a similar manner to the removal of TFIIK. Yeast genetic analysis suggests that both Pro51 and Arg64 of Tfb3 are required to maintain the stability of the Tfb3–pol II interface in the PIC. Cryo-electron microscopy analysis of a yeast PIC lacking TFIIK reveals considerable variability in the orientation of TFIIH, which impairs TSS scanning after promoter opening.
期刊介绍:
Nucleic Acids Research (NAR) is a scientific journal that publishes research on various aspects of nucleic acids and proteins involved in nucleic acid metabolism and interactions. It covers areas such as chemistry and synthetic biology, computational biology, gene regulation, chromatin and epigenetics, genome integrity, repair and replication, genomics, molecular biology, nucleic acid enzymes, RNA, and structural biology. The journal also includes a Survey and Summary section for brief reviews. Additionally, each year, the first issue is dedicated to biological databases, and an issue in July focuses on web-based software resources for the biological community. Nucleic Acids Research is indexed by several services including Abstracts on Hygiene and Communicable Diseases, Animal Breeding Abstracts, Agricultural Engineering Abstracts, Agbiotech News and Information, BIOSIS Previews, CAB Abstracts, and EMBASE.