sequencespecific

Sequence-specific describes interactions that depend on the exact order of nucleotides or amino acids in a molecule. In biology, it refers to binding or recognition that is determined by sequence rather than solely by overall shape or charge.

In nucleic acids, sequence specificity is exhibited by many proteins and enzymes that bind to particular DNA or RNA motifs. Transcription factors often recognize defined promoter or enhancer sequences, while restriction endonucleases cut DNA only at specific recognition sites. Nucleases associated with genome editing, such as those guided by a nucleic acid sequence, exemplify sequence-specific targeting, depending on the guide sequence and, for some systems, a neighboring PAM.

A sequence-specific interaction can be high-affinity and highly selective, but is often influenced by sequence context, methylation, or DNA topology, which can modify binding affinity.

Proteins can also display sequence specificity toward amino acid sequences or motifs, as seen in proteases that recognize specific peptide sequences or signaling proteins that bind short motifs.

In diagnostics and research, sequence-specific probes and primers hybridize only to complementary sequences, enabling assays to distinguish among closely related targets.

Conceptually, sequence specificity contrasts with structure-specific or nonspecific interactions. It is a central consideration in understanding gene regulation, enzymology, and molecular recognition.