細胞極性タンパク質LGNとパートナー分子mInsc複合体の認識機構

抄録

Interaction between the mammalian cell polarity proteins Inscuteable (mInsc) and LGN plays crucial roles in mitotic spindle orientation, a process contributing to asymmetric cell division. We describe here the crystal structure of the LGN-binding domain (LBD) of human mInsc in complex with the N-terminal TPR domain of human LGN at 2.6 Å resolution. mInsc-LBD adopts an elongated structure containing an α-helix and an antiparallel β-sheet linked by an extended region and runs antiparallel to LGN along the concave surface of the superhelix formed by the TPR motifs, indicative of a novel mode for TPR interaction. Characteristics of interaction between LGN TPR domain and other partner molecules are discussed.