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Updated: May 30, 2026

In Vitro Directed Evolution of a Restriction Endonuclease with More Stringent Specificity
Published on: March 25, 2020
Chemically-induced affinity star restriction specificity: a novel TspGWI/sinefungin endonuclease with theoretical
Agnieszka Zylicz-Stachula1, Olga Zołnierkiewicz, Joanna Jeżewska-Frąckowiak
1Division of Theoretical Physical Chemistry, Department of Chemistry, University of Gdańsk, Poland.
Abstract:
The type IIS/IIC restriction endonuclease TspGWI recognizes the sequence 5'-ACGGA-3', cleaving DNA 11/9 nucleotides downstream. Here we show that sinefungin, a cofactor analog of S-adenosyl methionine, induces a unique type of relaxation in DNA recognition specificity. In the presence of sinefungin, TspGWI recognizes and cleaves at least 12 degenerate variants of the original recognition sequence that vary by single base pair changes from the original 5-bp restriction site with only a single degeneracy per variant appearing to be allowed. In addition, sinefungin was found to have a stimulatory effect on cleavage at these nondegenerate TspGWI recognition sites, irrespective of their number or the DNA topology. Interestingly, no fixed "core" could be identified among the new recognition sequences. Theoretically, TspGWI cleaves DNA every 1024 bp, while sinefungin-induced activity cleaves every 78.8 bp, corresponding to a putative 3-bp long recognition site. Thus, the combination of sinefungin and TspGWI represents a novel frequent cutter, next only to CviJI/CviJI*, that should prove useful in DNA cloning methodologies.
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