Coding

Part:BBa_K2415000

Designed by: Yunping Lin   Group: iGEM17_GZHS-United   (2017-10-20)
Revision as of 02:13, 22 October 2017 by Linyunping (Talk | contribs)


Cry4Ba

Cry4Ba is an 130kDa insecticidal crystal proteins(ICP) that can be isolated from Bacillus thuringiensis subsp. israelensis (Bti). It is specifically toxic against Aedes and Anopheles mosquitoes larvae which are the vectors of Dengue virus, yellow fever virus, and malaria parasite. The Cry inclusions are solubilized in the midgut lumen of susceptible insects larvae at alkaline pH for both dipterans and lepidopterans, and proteolytically activated by gut proteases to yield the active toxins of ~65-kDa. Subsequently, the activated toxins bind specifically to a variety of receptors such as GPI (glycosylphosphatidyl inositol)-anchored aminopeptidase-N and GPI-anchored alkaline phosphatase that are found on the brush-border membrane (BBM) of midgut epithelial cells. This toxin-receptor interaction can assist toxin penetration into the cell membrane, leading to the formation of ion-permeable pores and eventually causeing osmotic lysis of target cells.

Sporulating cells of Bacillus thuringiensis (Bti) can produce insecticidal crystal proteins, or ICPs. The ICPs are classified by amino acid sequence homology into two main families, the Cry and the Cyt toxins. Cry insecticidal proteins, which are known as δ-endotoxins, are produced by the Gram-positive soil bacterium Bacillus thuringiensis (Bti) produced in the form of crystalline inclusions during sporulation. These crystal toxins are cytolytic pore-forming toxins that are lethal to various insect larvae.

The structure of Cry toxin shows a common topology composed of three domains. Domain I is an a-helix bundle, which is believed to be responsible for pore formation on the basis of its structural characteristics. Domain II is a b-prism of three antiparallel sheets with loops ending at its apex, which is thought to be involved in receptor binding. Domain III is a lectin-like b-sandwich, which is important to the stability of the toxin, and has been found to participate in determining toxin specificity.

<T--GZHS-United--result2.png>

Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal NheI site found at 69
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal NgoMIV site found at 2493
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal BsaI.rc site found at 475


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