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Proteins that contain an SH3 (src homology 3) domain are likely to bind to which of the following features of a protein partner?

A) Phosphorylated tyrosine residues
B) DNA sequences
C) α-helical regions
D) Glycosylated serine residues

1 Answer

6 votes

Final answer:

Proteins with an SH3 domain typically bind to proline-rich motifs in other proteins, rather than binding to phosphorylated tyrosine residues, DNA sequences, α-helical regions, or glycosylated serine residues. Phosphorylation of serine, threonine, and tyrosine is due to the hydroxyl groups present in these amino acids.

Step-by-step explanation:

Proteins that contain an SH3 (src homology 3) domain are likely to bind to protein partners with proline-rich motifs or sequences. The SH3 domain recognizes and binds to these distinct sequences, which are often found in other signaling proteins. This interaction plays a critical role in cellular communication and signal transduction pathways.

Regarding the options provided in the question, the SH3 domain does not specifically bind to phosphorylated tyrosine residues, DNA sequences, α-helical regions, or glycosylated serine residues. Instead, proteins with SH3 domains typically interact with polyproline sequences which are not characterized by phosphorylation, specific interaction with DNA, a helical structure, or glycosylation.

As it pertains to phosphorylation, it's important to note that the enzymatic phosphorylation of serine, threonine, and tyrosine residues is facilitated by the presence of a hydroxyl group in their side chains, which allows them to be targeted by kinase enzymes that add phosphate groups from ATP.

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