転写開始とその調節の新モデル

抄録

Transcription initiation is a multi-step reaction. The conventional model is sequential, but fails to explain kinetic behaviors of abortive syntheses from some promoters, existence of inactive transcription complex, and different yields of full-length transcripts in vitro from different promoters. These are explained by a new model which is derived from our kinetic study on abortive synthesis. This new model has two branched pathways; one leads to fulllength synthesis and the other to inactivation via a transcription complex which produces only abortive transcript. This model may help the structural understanding of transcriptional regulation of both initiation and elongation, which is based on recent progress in structural biology of transcription like bending of DNA template, apparent discontinuous movements of RNA polymerase, and different spatial relationship among catalytic center, RNA and DNA.