High fidelity restriction endonucleases

摘要

Compositions and methods are provided for enzymes with altered properties that involve a systematic approach to mutagenesis and a screening assay that permits selection of the desired proteins. Embodiments of the method are particularly suited for modifying specific properties of restriction endonucleases such as star activity. The compositions includes restriction endonucleases with reduced star activity as defined by an overall fidelity index improvement factor.

主权项

1. A composition comprising a variant SacI restriction endonuclease having reduced star activity, wherein the variant SacI restriction endonuclease comprises an amino acid sequence that differs from the amino acid sequence of the parent SacI restriction endonuclease by substitutions at positions corresponding to positions 117 and 200 in SEQ ID NO:93.