Difference between revisions of "Part:BBa K3071013"

Revision as of 10:57, 19 October 2019

PspA promoter

Description

This is an regulatory element that originated from Escherichia coli K12 strain. This basic part is used to construct our composite part (BBa_K3071014). Our rt-qPCR data show that this promotor is able to initiate the transcription in form of synthetic construct.

Biology

pspA promotor is a sigma-54 (σ-54) regulated activator dependent promotor. In the pspA promoter upstream region, it contains σ-54 consensus sequence 5' of the start contains a GG doublet as -24 and a consensus GG doublet at -12, the high-affinity IHF site (-25 to -60), as well as the UAS sites (UAS I: -89 to -107; UAS II:-111 to -129).

Usage

sigm54-RNA holoenzyme (σ-54 RNAP) forms an inactive transcriptional initiation complex on this promotor, which can be activated in E. coli by the bacterial enhancer-binding protein PspF (BBa_K3071006). PspF functions by binding to the upstream activation sequences (UAS) near the promoter and contacting the promotor-bound σ-54 RNAP via DNA looping stabilized by the binding of integration host factor (IHF). Previous research has demonstrated the property of pspF-dependent and enhancer-specific transcription activation of pspA promotor.

Characterization

The UAS sites of this promotor are replaced by CBS I(BBa_K3071011) and CBSII (BBa_K3071012) in our own synthetic system to construct CBS I & II-regulated pspA promotor (BBa_K3071014). The rt-qPCR data upon activation indicate a significant change in gene expression, suggest the related composite part is functional. More detail could refer to part information in (BBa_K3071014) Sequence and Features