Question

Which of the following are true for SH2 domains?

A. SH2 domains in proteins can bind phosphotyrosine residues in any amino acid sequence context when a tyrosine residue is phosphorylated
B. SH2 domains are quite interchangeable with PTB domains and both can bind to any site in a receptor that is phosphorylated on tyrosine
C. Most SH2 domains bind in a phosphorylation-dependent manner to
phosphotyrosine in a specific amino acid sequence context that utilizes lower affinity interactions to bind to protein sequences C-terminal to the phosphotyrosine
D. Most SH2 domains bind in a phosphorylation-dependent manner to phosphotyrosines in a specific amino acid sequence context that utilizes lower affinity interactions to bind protein sequences N-terminal to the phosphotyrosine
E. None of the above

Answer 1

SH2 domains specifically bind phosphotyrosine in a sequence-specific context C-terminal to the phosphotyrosine, playing a pivotal role in cellular signaling.

Step-by-step explanation:

The correct answer to the question on SH2 domains is option C. Most SH2 domains bind in a phosphorylation-dependent manner to phosphotyrosine in a specific amino acid sequence context that utilizes lower affinity interactions to bind to protein sequences C-terminal to the phosphotyrosine.

SH2 domains are specialized protein modules that bind phosphotyrosine residues on target proteins. This interaction is critical for the transmission of cellular signals and typically occurs in a highly specific context defined by the amino acid sequence adjacent to the phosphotyrosine residue.

Unlike SH2 domains, PTB domains may bind to sequences N-terminal to the phosphotyrosine, making option B incorrect. SH2 domains do not bind to just any phosphorylated tyrosine in any sequence context, as suggested in option A, making specificity a key feature of their function.