Part:BBa_K566012

cI repressor from Lambda phage optimized for E. coli cI (+LVA)

cI repressor from Lambda phage optimized for E. coli. Includes LVA tag.

Preferential codons to improve their expression in E. coli.

Usage and Biology

The lambda repressor is a dimeric protein also known as the cI protein. Lambda cI protein has the capability to bind several operators within a complex regulatory region that involves mainly three promoters (pRM, pR and pL). There are two well-known sets of cI binding sites in lambda (OR and OL) spaced 2.4 kb apart and composed of three operators each (OR1:OR2:OR3; OL1:OL2:OL3) (figure 1). cI has a higher affinity for OR1 and OR2 operators, where binding positively regulates the pRM promoter. On the other hand, when bound to OR3 cI represses the promoter; however, due to a low binding affinity, a higher concentration of the protein is required. Thus, cI can act as both an activator -at low concentrations- and a repressor -at high concentrations- on pRM. Modified with a LVA tag for rapid degradation of the protein.

Figure 1. The λ operators OL and OR. The promoter pRM transcribes cI, rexA, and rexB in a lysogen, which sum up to size of ∼2.4 Kb. Figure taken and modified from Court DL et al. (2007) J Bacteriol 189:298–304. .

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
  INCOMPATIBLE WITH RFC[25]

  Illegal AgeI site found at 463
  
• 1000
  COMPATIBLE WITH RFC[1000]