To obtain a new DNA polymerase capable of joining with a human acquired immune deficiency syndrome virus promoter, having a DNA-binding region at a place near the N-terminal, and capable of producing the DNA, an antibody, etc., useful for diagnosing, preventing and treating cancers, virus- infected diseases, etc.

This new DNA polymerase can bind to a human acquired immune deficiency syndrome virus promoter, has a mol.wt. (monomer) of 57.6 kDa, has a leucine zipper structure, has a DNA-binding domain at a place near the N-terminal, contains a region having homology with the DNA polymerase of Escherichia coil in an extent of approximately 60% or more and comprising approximately 430 residual groups, exhibits a DNA-polymerizing activity in the presence of a double-strand DNA as a template in the coexistence of a cell nucleus extract, and has such a nature that the gene exhibits the maximum expression against a multiplication stimulation within a hour and exhibits the expression lowered after the maximum expression. The enzyme is obtained by screening a human T-cell lymphoma culture cell cDNA library with a synthesized probe, joining the obtained gene with a vector, and subsequently expressing the polymerase in a host cell.