| abstract |
Thermostable Cas9 nuclease. The present invention relates to the field of genetic engineering, and more particularly to nucleic acid editing and genome modification. The present invention provides an isolated Cas protein or polypeptide fragment thereof having the amino acid sequence of SEQ ID NO: 1 or a sequence at least 77% identical thereto. A Cas protein or polypeptide can bind, cleave, label, or modify a double-stranded target polynucleotide at a temperature ranging from 30 ° C to 100 ° C. The present invention further provides an isolated nucleic acid molecule, an expression vector and a host cell encoding the Cas9 nuclease. The invention also provides a PAM sequence recognized by a Cas protein or polypeptide. The Cas9 nuclease disclosed herein has become a novel tool for genetic engineering at high temperatures and is of particular value in genetic engineering of thermophilic organisms, especially microorganisms. |