Revision as of 11:10, 1 November 2017

Rop protein with anderson (0) promoter for global plasmid copy number control

This construct is an intermediate to full SynORI global copy number control device. It consists of a weak Anderson promoter, weak Anderson RBS, ROP protein and a double terminator.

When placed in a SynORI system this device lowers plasmid copy number of each group as it can bypass the selective control.

Device also works with other plasmids consisting of ColE1 origin of replication

Devices from the same series that have different Anderson promoters: part:BBa_K2259072 (0 Anderson), part:BBa_K2259073 (0.15 Anderson), part:K2259074 (0.24 Anderson).

See how this part fits into the whole SynORI framework by pressing here!

Sequence and Features

Introduction

Biology

ColE1 plasmid replication overview

Figure 1. Main principles of ColE1 plasmid family replication. (Citation needed)

ColE1-type plasmid replication begins with the synthesis of plasmid encoded RNA II (also called primer transcript) by RNA polymerase which initiates transcription at a site 555bp upstream of origin of replication. The RNA transcript forms a RNA - DNA hybrid with template DNA near the origin of replication. Hybridized RNA is then cleaved at the replication origin by RNAse H and serves as a primer for DNA synthesis by DNA polymerase I (Figure 1. A).

Initiation of replication can be inhibited by plasmid encoded small RNA, called RNA I . Synthesis of RNA I starts 445 bp upstream of the replication origin and proceeds in the direction opposite to that of RNA II synthesis and terminates near the RNA II transcription initiation site. RNA I binds to RNA II and thereby prevents the formation of a secondary structure of RNA II that is necessary for hybridization of RNA II to the template DNA (Figure 1. B).

For RNA I to inhibit primer formation, it must bind before the nascent RNA II transcript extends to the replication origin. Consequently, the concentration of RNA I and the rate of binding of RNA I to RNA II is critical for regulation of primer formation and thus for plasmid replication.

The interaction between RNA I and RNA II can be amplified by Rop protein, see part:BBa_K2259010.

Rop dimer is a bundle of four tightly packed alpha helices that are held by hydrophobic interactions (Fig. 2).

Usage with SynORI (Framework for multi-plasmid systems)

About SynORI

SynORI is a framework for multi-plasmid systems created by Vilnius-Lithuania 2017 which enables quick and easy workflow with multiple plasmids, while also allowing to freely pick and modulate copy number for every unique plasmid group! Read more about [http://2017.igem.org/Team:Vilnius-Lithuania SynORI here]!

This device in SynORI

This is a constitutive global copy number modulator device which lowers plasmid copy number of every group in the system bypassing the selective control of different groups. These constitutive devices can be used with different Anderson promoters to select a different copy number.

Devices from the same series that have different Anderson promoters: part:BBa_K2259072 (0 Anderson), part:BBa_K2259073 (0.15 Anderson), part:K2259074 (0.24 Anderson).

See the [http://2017.igem.org/Team:Vilnius-Lithuania Vilnius-Lithuania 2017 team wiki] for more insight about our synthetic origin of replication (SynORI).

Further details

For more background information and indepth insight on this part's design please see the individual part page of ROP proteinpart:BBa_K2259010.

Characterization

In order to characterize this construct, it must be cloned next to RNA II gene. Please see part:BBa_K2259052.

References