Grasp a pTyr-peptide by its SOCS. 
Signaling via suppressors of cytokine signaling (SOCS) is an important negative feedback system for cytokine-mediated signal transduction.  Recently in Molecular Cell, Babon et al. ( 2006) described the tertiary structure of SOCS3 in complex with a phosphotyrosine-containing peptide from the IL-6 receptor subunit gp130, and they identified the specific amino acids that are critical for binding.