DNA secondary structure formation by DNA shuffling of the conserved domains of the Cry protein of .

Authors:
Efrain H Pinzon
Efrain H Pinzon
Laboratory of Biotechnology and Molecular Biology
Daniel A Sierra
Daniel A Sierra
University of Connecticut
Miguel O Suarez
Miguel O Suarez
Laboratory of Biotechnology and Molecular Biology
Alvaro M Florez
Alvaro M Florez
Laboratory of Biotechnology and Molecular Biology
Ithaca | United States

BMC Biophys 2017 22;10. Epub 2017 May 22.

Laboratory of Biotechnology and Molecular Biology, MASIRA Institute, School of Health, University of Santander, UDES, Bucaramanga, Colombia.

Background: The Cry toxins, or δ-endotoxins, are a diverse group of proteins produced by . While DNA secondary structures are biologically relevant, it is unknown if such structures are formed in regions encoding conserved domains of Cry toxins under shuffling conditions. We analyzed 5 holotypes that encode Cry toxins and that grouped into 4 clusters according to their phylogenetic closeness. The mean number of DNA secondary structures that formed and the mean Gibbs free energy [Formula: see text] were determined by an analysis using different experimental DNA shuffling scenarios. In terms of spontaneity, shuffling efficiency was directly proportional to the formation of secondary structures but inversely proportional to ∆G.

Results: The results showed a shared thermodynamic pattern for each cluster and relationships among sequences that are phylogenetically close at the protein level. The regions of the and genes that encode domain I showed more spontaneity and thus a greater tendency to form secondary structures (<∆G). In the region of domain III; this tendency was lower (>∆G) in the and genes. Proteins that are phylogenetically closer to Cry11Ba and Cry11Bb, such as Cry2Aa and Cry18Aa, maintained the same thermodynamic pattern. More distant proteins, such as Cry1Aa, Cry1Ab, Cry30Aa and Cry30Ca, featured different thermodynamic patterns in their DNA.

Conclusion: These results suggest the presence of thermodynamic variations associated to the formation of secondary structures and an evolutionary relationship with regions that encode highly conserved domains in Cry proteins. The findings of this study may have a role in the design of gene assembly by DNA shuffling techniques.

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http://dx.doi.org/10.1186/s13628-017-0036-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5441083PMC
May 2017
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