Direct observation of abortive initiation and promoter escape within single immobilized transcription complexes.

Using total-internal-reflection fluorescence microscopy equipped with alternating-laser excitation, we were able to detect abortive initiation and promoter escape within single immobilized transcription complexes. Our approach uses fluorescence resonance energy transfer to monitor distances between...

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Main Authors: Margeat, E, Kapanidis, A, Tinnefeld, P, Wang, Y, Mukhopadhyay, J, Ebright, R, Weiss, S
Format: Journal article
Language:English
Published: 2006
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author Margeat, E
Kapanidis, A
Tinnefeld, P
Wang, Y
Mukhopadhyay, J
Ebright, R
Weiss, S
author_facet Margeat, E
Kapanidis, A
Tinnefeld, P
Wang, Y
Mukhopadhyay, J
Ebright, R
Weiss, S
author_sort Margeat, E
collection OXFORD
description Using total-internal-reflection fluorescence microscopy equipped with alternating-laser excitation, we were able to detect abortive initiation and promoter escape within single immobilized transcription complexes. Our approach uses fluorescence resonance energy transfer to monitor distances between a fluorescent probe incorporated in RNA polymerase (RNAP) and a fluorescent probe incorporated in DNA. We observe small, but reproducible and abortive-product-length-dependent, decreases in distance between the RNAP leading edge and DNA downstream of RNAP upon abortive initiation, and we observe large decreases in distance upon promoter escape. Inspection of population distributions and single-molecule time traces for abortive initiation indicates that, at a consensus promoter, at saturating ribonucleoside triphosphate concentrations, abortive-product release is rate-limiting (i.e., abortive-product synthesis and RNAP-active-center forward translocation are fast, whereas abortive-product dissociation and RNAP-active-center reverse translocation are slow). The results obtained using this new methodology confirm and extend those obtained from diffusing single molecules, and pave the way for real-time, single-molecule observations of the transitions between various states of the transcription complex throughout transcription.
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spelling oxford-uuid:fb92adf1-1358-4bde-9e81-ee6de21035572022-03-27T13:14:49ZDirect observation of abortive initiation and promoter escape within single immobilized transcription complexes.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:fb92adf1-1358-4bde-9e81-ee6de2103557EnglishSymplectic Elements at Oxford2006Margeat, EKapanidis, ATinnefeld, PWang, YMukhopadhyay, JEbright, RWeiss, SUsing total-internal-reflection fluorescence microscopy equipped with alternating-laser excitation, we were able to detect abortive initiation and promoter escape within single immobilized transcription complexes. Our approach uses fluorescence resonance energy transfer to monitor distances between a fluorescent probe incorporated in RNA polymerase (RNAP) and a fluorescent probe incorporated in DNA. We observe small, but reproducible and abortive-product-length-dependent, decreases in distance between the RNAP leading edge and DNA downstream of RNAP upon abortive initiation, and we observe large decreases in distance upon promoter escape. Inspection of population distributions and single-molecule time traces for abortive initiation indicates that, at a consensus promoter, at saturating ribonucleoside triphosphate concentrations, abortive-product release is rate-limiting (i.e., abortive-product synthesis and RNAP-active-center forward translocation are fast, whereas abortive-product dissociation and RNAP-active-center reverse translocation are slow). The results obtained using this new methodology confirm and extend those obtained from diffusing single molecules, and pave the way for real-time, single-molecule observations of the transitions between various states of the transcription complex throughout transcription.
spellingShingle Margeat, E
Kapanidis, A
Tinnefeld, P
Wang, Y
Mukhopadhyay, J
Ebright, R
Weiss, S
Direct observation of abortive initiation and promoter escape within single immobilized transcription complexes.
title Direct observation of abortive initiation and promoter escape within single immobilized transcription complexes.
title_full Direct observation of abortive initiation and promoter escape within single immobilized transcription complexes.
title_fullStr Direct observation of abortive initiation and promoter escape within single immobilized transcription complexes.
title_full_unstemmed Direct observation of abortive initiation and promoter escape within single immobilized transcription complexes.
title_short Direct observation of abortive initiation and promoter escape within single immobilized transcription complexes.
title_sort direct observation of abortive initiation and promoter escape within single immobilized transcription complexes
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AT tinnefeldp directobservationofabortiveinitiationandpromoterescapewithinsingleimmobilizedtranscriptioncomplexes
AT wangy directobservationofabortiveinitiationandpromoterescapewithinsingleimmobilizedtranscriptioncomplexes
AT mukhopadhyayj directobservationofabortiveinitiationandpromoterescapewithinsingleimmobilizedtranscriptioncomplexes
AT ebrightr directobservationofabortiveinitiationandpromoterescapewithinsingleimmobilizedtranscriptioncomplexes
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