Transformed cell and method for producing linear covalently closed DNA

Abstract

The present invention addresses the problem of providing a novel method for simply and efficiently producing linear covalently closed DNA.　The present invention provides a transformed cell containing a first double-stranded circular DNA vector and a second double-stranded circular DNA vector. The transformed cell contains a protelomerase gene sequence encoding protelomerase or an active fragment thereof and placed under the control of a promoter capable of regulating expression and an endonuclease gene sequence encoding endonuclease or an active fragment thereof and placed under the control of a promoter capable of regulating expression. The first double-stranded circular DNA vector contains a pair of protelomerase recognition sequences that are recognized and cleaved by the protelomerase or the active fragment thereof, a target nucleic acid sequence that is placed in a region between the pair of protelomerase recognition sequences, and at least one endonuclease recognition sequence that is placed in another region between the pair of protelomerase recognition sequences and is recognized and cleaved by the endonuclease or the active fragment thereof. The second double-stranded circular DNA vector contains the protelomerase gene sequence and / or the endonuclease gene sequence and also contains at least one endonuclease recognition sequence that is recognized and cleaved by the endonuclease or the active fragment thereof.