What does DNase I primarily target for digestion?

DNase I primarily targets double-stranded DNA for digestion. It is an enzyme that cleaves the phosphodiester bonds within the DNA strands, which leads to the breakdown of the double helix structure.

The action of DNase I is significant because it is pivotal in various biological processes such as apoptosis, where it degrades nuclear DNA, and in laboratory settings, where it can be used to eliminate contamination in samples. The enzyme recognizes and acts on the double-stranded regions, rather than being restricted to a specific context like single strands or particular nucleotide compositions.

The misconception regarding the other options lies in their specificity: DNase I does not specifically target individual nucleotides like pyrimidines or regions enriched in A-T bases, nor does it function primarily on single DNA strands. Thus, the focus of DNase I's activity is on double-stranded DNA, making the recognition of this enzyme's action crucial for understanding its role in both biological and research environments.