Modified CtPif1 helicase and application thereof

The invention belongs to the field of gene engineering and genetic engineering, and discloses a modified CtPif1 helicase, a complex containing the helicase, a construction body containing the helicase, a method for representing target polynucleotide by adopting the helicase or the complex or the construction body, and application of the modified CtPif1 helicase. The modified CtPif1 helicase and the complex and the construct thereof provided by the invention can control the movement of polynucleotide passing through a biological nanopore, and especially when the length of a polynucleotide chain is increased, the modified CtPif1 helicase can still stably control the movement of the polynucleotide without falling off from the polynucleotide. The invention further provides a specific CtPif1 helicase mutant, and the capacity of the specific CtPif1 helicase mutant for controlling polynucleotide to penetrate through a nanopore to move is improved. 本发明属于基因工程和遗传工程领域，公开了一种修饰的CtPif1解旋酶，包含该解旋酶的复合体，包含该解旋酶的构建体，以及采用该解旋酶或复合体