Crystal structure of the middle domain of human poly(A)-binding protein-interacting protein 1

► We determined the crystal structure of the middle domain of Paip1 isoform 2 (Paip1M). ► This is the first three-dimensional structure of a member of the Paip family. ► Paip1M comprises five HEAT domains. ► The amino-acid sequence motif of Paip1M involved in binding of eIF4A is conserved.