2015 年 57 巻 6 号 p. 324-330
ULK complex is the most upstream factor to initiate autophagy in higher eukaryotes. Atg101 is an essential component of the complex, but is absent from the functionally equivalent Atg1 complex in budding yeast. To elucidate the molecular functions of Atg101, we have determined the crystal structure of Atg101 complexed with Atg13. The structure reveals that Atg101 is a member of the HORMA family protein and is structurally similar to Atg13. Structure-based mutational studies reveal that Atg101 has at least two critical functions in autophagy: one is to stabilize Atg13 and the other is to recruit downstream Atg factors to autophagosome formation site.