Binding sites for calcium, lipid and p11 on p36, the substrate of retroviral tyrosine‐specific protein kinases

Abstract

Biochemical and partial sequence data reveal the two‐domain structure of p36. A loose structure of some 30 residues at the amino‐terminus contains the phosphorylatable tyrosine and the binding site for the p11 regulatory chain. The following p33 domain retains the lipid‐binding site as well as the Ca²⁺ site which influences the spectral properties of the single tryptophan and one tyrosine. The combined sequence data covering about 25% of the molecule identify p36 as a unique polypeptide.