Binds to dsDNA in a sequence-specific manner. Also binds a DNA/RNA duplex when the recognized sequence is in the DNA strand. Each tandem core repeat recognizes a single nucleotide in the target DNA via its base-specifying residue (BSR, residue 13 of each repeat); altering this amino acid changes sequence specificity. The protein is composed of 20 tandem core repeats (the BuD domain) with 1 base-specifying residue (BSR, residue 13), which recognizes 1 base pair in the target DNA. After addition of nuclear localization signals (NLS) and a transcription activation domain, can be expressed in both human and plant cells and will recognize and transcribe a target sequence; more than 17 core repeats are necessary for this function. The N-terminal cryptic repeats effect activation, while the C-terminal cryptic repeat is absolutely required. When fused to the FokI restriction endonuclease domain functions as a sequence-specific DNA nuclease in vitro (called TALE-nuclease, TALEN, PubMed:24792163 or BuDN, PubMed:25004980) and with an NLS, in human and yeast cells. The latter construct also allows targeted gene insertion. Modification of the core repeat BSR allows recognition of a user-defined DNA sequence, allowing these constructs to target and modify a DNA sequence of interest, and thus be used for genome engineering. Other potential uses as transcriptional repressors, for transposon targeting, DNA methylation or histone tail modifictions are also possible. Belongs to the transcription activator-like effector (TALE) family. Bat subfamily.