Part:BBa_I739103

Double Promoter (lacI, negative / P22 cII, negative)

Part Structure

The Biobrick consists of a large part of the non-constitutive promoter BBa_R011 (Basepairs 1-48) linked to twice the first operator sequence of BBa_R0053 (OR1).

The -35 and -10 regions, which are responsible for the binding of RNA-polymerase to DNA via sigma factors, are included in the BBa_R0011 promoter region (first part of the double promoter). No further functional -10 and -35 regions were included in the second part of the double promoter. Instead, two operator sequences of the same type were included in the second part. The reason for this is that the probability of a binding event (and hence regulation strength) is increased if a multiple of identical operator sequences is included in the regulatory sequence.

Summarized:
There are four operator sequences: 2xBBa_R0011 (lac O1), 2xBBa_R0053 (OR1).

Mode of Action

Regulation of the first part: When LacI binds to the pLac operator sequences, it represses transcription. If the inducer [http://openwetware.org/wiki/IPTG Isopropyl-beta-D-thiogalactopyranoside (IPTG)] is added, LacI action is inhibited and the promoter gets derepressed.

Regulation of the second part: When P22 cII binds to the P22 cII operator sequences, it represses transcription. There is no inducer which derepresses the promoter upon addition.

Purpose

This Biobrick was designed for the [http://2007.igem.org/ETHZ ETHZ iGEM 2007 project] and belongs to a first generation of double promoters. BBa_I739103 is part of biobrick BBa_I739008.

Testing

Checked for uniqueness of restriction enzyme cleavage sites:
Eco: ok
Xba: ok
Spe: ok
Pst: ok

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]