Analysis of HIV Nef Dimerization and Binding Partner Interactions by Hydrogen Exchange Mass Spectrometry

摘要

Nef is an HIV accessory protein with no catalytic activity that binds to a number of proteins in cells, including the Src-family kinase Hck. The protein is myristoylated at the N-terminus for membrane localization, with an α-helix in the otherwise unstructured N-terminal anchor domain and a mostly structured core domain (Figure 1a). The core (residues 63-210) contains a proline-rich region for interaction with Hck and other Srcfamily kinases through their SH3 domains, an acidic cluster essential for immune receptor downregulation, and an internal flexible loop involved in CD4 downregulation. Limited structural data exist for full-length Nef. The Nef core domain is more amenable to crystallization and has been solved in complex with various binding partners. The Nterminal portion has also been studied in isolation, and a model was created using these data to visualize the full length protein (Figure 1b).