Abortive Initiation and Productive Initiation by RNA Polymerase Involve DNA Scrunching.

Andrey Revyakin (1, 2) , Chenyu Liu (1, 2, 3) , Richard H. Ebright (1) , Terence R. Strick . (2, 3)

1 H.H.M.. - Howard Hughes Medical Institute, Waksman Institute, and Department of Chemistry
2 CSHL - Cold Spring Harbor Laboratory
3 IJM (UMR_7592) - Institut Jacques Monod

Using single-molecule DNA nanomanipulation, we show that abortive initiation involves DNA "scrunching"-in which RNA polymerase (RNAP) remains stationary and unwinds and pulls downstream DNA into itself-and that scrunching requires RNA synthesis and depends on RNA length. We show further that promoter escape involves scrunching, and that scrunching occurs in most or all instances of promoter escape. Our results support the existence of an obligatory stressed intermediate, with approximately one turn of additional DNA unwinding, in escape and are consistent with the proposal that stress in this intermediate provides the driving force to break RNAP-promoter and RNAP-initiation-factor interactions in escape.

Domaines: Biologie moléculaire

Andrey Revyakin, Chenyu Liu, Richard H. Ebright, Terence R. Strick .. Abortive Initiation and Productive Initiation by RNA Polymerase Involve DNA Scrunching.. Science, 2006, 314 (5802), pp.1139-1143. ⟨10.1126/science.1131398⟩. ⟨hal-00115689⟩