TY - JOUR
T1 - Different types of pausing modes during transcription initiation
AU - Lerner, Eitan
AU - Ingargiola, Antonino
AU - Lee, Jookyung J.
AU - Borukhov, Sergei
AU - Michalet, Xavier
AU - Weiss, Shimon
N1 - Publisher Copyright:
© 2017 Taylor & Francis.
PY - 2017/8/8
Y1 - 2017/8/8
N2 - In many cases, initiation is rate limiting to transcription. This due in part to the multiple cycles of abortive transcription that delay promoter escape and the transition from initiation to elongation. Pausing of transcription in initiation can further delay promoter escape. The previously hypothesized pausing in initiation was confirmed by two recent studies from Duchi et al.1 and from Lerner, Chung et al.2 In both studies, pausing is attributed to a lack of forward translocation of the nascent transcript during initiation. However, the two works report on different pausing mechanisms. Duchi et al. report on pausing that occurs during initiation predominantly on-pathway of transcript synthesis. Lerner, Chung et al. report on pausing during initiation as a result of RNAP backtracking, which is off-pathway to transcript synthesis. Here, we discuss these studies, together with additional experimental results from single-molecule FRET focusing on a specific distance within the transcription bubble. We show that the results of these studies are complementary to each other and are consistent with a model involving two types of pauses in initiation: a short-lived pause that occurs in the translocation of a 6-mer nascent transcript and a long-lived pause that occurs as a result of 1–2 nucleotide backtracking of a 7-mer transcript.
AB - In many cases, initiation is rate limiting to transcription. This due in part to the multiple cycles of abortive transcription that delay promoter escape and the transition from initiation to elongation. Pausing of transcription in initiation can further delay promoter escape. The previously hypothesized pausing in initiation was confirmed by two recent studies from Duchi et al.1 and from Lerner, Chung et al.2 In both studies, pausing is attributed to a lack of forward translocation of the nascent transcript during initiation. However, the two works report on different pausing mechanisms. Duchi et al. report on pausing that occurs during initiation predominantly on-pathway of transcript synthesis. Lerner, Chung et al. report on pausing during initiation as a result of RNAP backtracking, which is off-pathway to transcript synthesis. Here, we discuss these studies, together with additional experimental results from single-molecule FRET focusing on a specific distance within the transcription bubble. We show that the results of these studies are complementary to each other and are consistent with a model involving two types of pauses in initiation: a short-lived pause that occurs in the translocation of a 6-mer nascent transcript and a long-lived pause that occurs as a result of 1–2 nucleotide backtracking of a 7-mer transcript.
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U2 - 10.1080/21541264.2017.1308853
DO - 10.1080/21541264.2017.1308853
M3 - Review article
C2 - 28332923
AN - SCOPUS:85028807450
SN - 2154-1264
VL - 8
SP - 242
EP - 253
JO - Transcription
JF - Transcription
IS - 4
ER -