nucleotidebound
Nucleotidebound is an adjective used in biochemistry and structural biology to describe a molecule, most commonly a protein, that has a nucleotide bound in a specific site. The bound nucleotide can be any cellular nucleotide, typically adenosine or guanosine triphosphates and their diphosphate forms (ATP, ADP, GTP, GDP). Nucleotide binding often induces conformational changes that regulate activity, stability, or interactions with other molecules. In many proteins the nucleotide state acts as a molecular switch, enabling transitions between different functional forms.
In proteins such as small GTPases, the nucleotide-bound state determines activity: GTP-bound forms are typically active,
In structural biology, nucleotidebound forms are described in crystal structures, cryo-electron microscopy reconstructions, or NMR studies
The concept is also important in drug design and protein engineering, where altering nucleotide binding can