Part:BBa_K2722002

6 times Chi recombination hotspot to inhibit Exonuclease V (RecBCD) activity

Chi is a short DNA Sequence, that is recognised by the RecBCD complex, also called Exonuclease V. Six Chi sites in a row can be used to inhibit RecBCD enzyme.

The RecBCD enzyme is both a helicase that unwinds, or separates the strands of DNA, and a nuclease that makes single-stranded nicks in DNA.(1) RecBCD complex is essential for cell viability as it plays an important role in repair of DNA double-strand breaks by initiating homologous recombination.(2)

However, RecBCD enzyme is also a highly processive at destruction of foreign DNA (3) The RecBCD enzyme is regulated by a cis-acting DNA sequence known as Chi (crossover hotspot instigator) that activates its recombination-promoting functions. Interaction with Chi causes an attenuation of the RecBCD enzyme's vigorous nuclease activity. (4)

Since Chi binds RecBCD with a greater affinity than other dsDNA substrate, this can be used to inhibit RecBCD activity in TX-TL, to more efficiently express linear DNA in TX-TL.

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]