Tyr402

Tyr402 is a designation used in protein sequence annotation to refer to the amino acid tyrosine at residue number 402 within a given protein. The specific protein carrying Tyr402 depends on the gene, isoform, or splice variant being considered, and numbering is relative to that protein’s primary structure.

As a tyrosine residue, Tyr402 can participate in various roles depending on its placement in the protein. It may contribute to catalytic activity, substrate recognition, or structural stability. Tyrosine can also undergo post-translational modifications, most commonly phosphorylation, which can regulate activity, localization, or interactions with other proteins. The hydroxyl group of tyrosine enables hydrogen bonding and, when modified, can introduce changes in charge and conformation.

In research, Tyr402 is often studied through targeted mutagenesis to probe its function. Replacing Tyr402 with phenylalanine (Tyr402Phe) removes the hydroxyl group to test the importance of phosphorylation or hydrogen bonding, while substitution with alanine (Tyr402Ala) can assess the contribution of side-chain size and hydrophobic interactions. Structural and biophysical methods, such as X-ray crystallography, NMR, or computational modeling, are commonly used to interpret Tyr402’s role in the local environment, including potential involvement in active or allosteric sites.

Because residue numbering is specific to a given sequence, Tyr402 is not a universal feature of all proteins and should be interpreted within the context of the defined protein sequence and structure.