[대학원 생명과학과 세미나 안내]
연사 : 정병천 박사(University of Texas Southwestern Medical Center)
연제 : Structural study of AAA+ ATPase TRIP13 in Spindle Checkpoint signaling
일시 : 2017년 6월 5일 (금) 오후 5시
장소 : 하나과학관 A동 101호
초청교수 : 송현규 교수
Abstract
TRIP13 (thyroid receptor-interacting protein 13) is AAA+ family ATPase and act as a protein remodeler that catalyzes Mad2 conformational change in the spindle checkpoint. The conformational change of Mad2 from a closed (cMad2) to open (oMad2) allows the disassembly of the mitotic checkpoint complex (MCC) including Mad2, BubR1, Bub3 and APC/C activator Cdc20 that takes place when the spindle checkpoint is off. The inactivation of the spindle checkpoint by dissociating MCC is promoted by TRIP13 with p31comet. Hexamer TRIP13 with ATP forms a complex with p31comet then hexamer TRIP13 also binds to Mad2 of MCC. The detailed mechanism of Mad2 conformation change by TRIP13-p31comet is still unknown. Here we have generated recombinant TRIP13 E253A (the catalytic dead mutant), cMad2 and p31comet∆N and succeeded making a complex of hexamer TRIP13 E253A with cMad2-p31comet∆N complex. We have screened a single protein complex particle by negative stain using electron microscope and performed a crystal screening to determine an atomic resolution structure of a ternary complex. During these screening, we have grown crystals and collected X-ray data at 2.5 Å resolution. Although it is a crystal structure of protomer TRIP13, the structure of human TRIP13 structure is determined and shows differences from c. elegance TRIP13 (PCH-2). The attempting to determine the ternary structure of TRIP13-Mad2-p31comet is still under way.