Dna cutting means based on cas9 protein from defluviimonas sp.

A method for generating a double-strand break in a genomic DNA sequence of a unicellular or multicellular organism directly adjacent to the sequence 5′-NN(G/A)NA(C/T)N-3′, comprising the introduction into at least one cell of said organism of an effective amount of:

• a) a protein comprising the amino acid sequence of SEQ ID NO:
• 1, or a nucleic acid encoding the protein comprising the amino acid sequence of SEQ ID NO:
• 1, and b) guide RNA comprising a sequence that forms a duplex with the nucleotide sequence of an organism's genomic DNA region, which is directly adjacent to the nucleotide sequence 5′-NN(G/A)NA(C/T)N-3′ and interacts with said protein following the formation of the duplex, or a DNA sequence encoding said guide RNA,
• wherein the interaction between said protein with the guide RNA and nucleotide sequence 5′-NN(G/A)NA(C/T)N-3′ results in the formation of a double-strand break in the genomic DNA sequence directly adjacent to the sequence 5′-NN(G/A)NA(C/T)N-3′.