Quantitative analysis of transcriptional pausing by Escherichia coli RNA polymerase: his leader pause site as paradigm.

摘要: Publisher Summary This chapter discusses the quantitative analysis of transcriptional pausing by Escherichia coli (E. coli) RNA polymerase. DNA-dependent polymerases do not synthesize chains at a constant rate. Instead, rapid elongation through some segments DNA is punctuated others. At pause sites, polymerase adds next NTP least 100 times more slowly than its optimal rate—that is, ∼75 nucleotides per second both in vivo when suppressed and vitro on nonpausing template poly[d(AT)]. Some sites occur strategic positions units where they halt facilitate interaction or nascent with regulatory factors. These factors may trigger termination directly (e.g., Rho), regulate subsequent event, alter pathway folding release from paused state. The describes basic methods to measure pausing, using E. his-leader site as paradigm. can be used test mechanism which recognizes escapes assess effects transacting it. Both experimental approach data are applicable eukaryotic well, for also appears play roles. stops transcription midway an operon leader region that includes leader-peptide-coding (the attenuator). Pausing delays arrival attenuation decision point until ribosome it control decision.