Fig. 7: Model for the GTP-dependent chaperone cycle of eEF1A biogenesis.
From: A ribosome-associating chaperone mediates GTP-driven vectorial folding of nascent eEF1A
Cartoon model emphasizing the GTP-driven chaperone mechanisms of the eEF1A folding pathway en route to the formation of eEF1A ternary complexes competent for translation elongation. The sequence begins with NAC UBA domain-dependent recruitment of Ypl225w upon eEF1A nascent chain emergence. Ypl225w uses its N-terminal ɑ-helix (NaH) to stabilize DI of eEF1A nascent chain until DI is able to bind GTP, at which point Ypl225w is released. Full-length eEF1A is subsequently chaperoned by Zpr1 using its ɑ-helical hairpin (aHH) and zinc finger domain (ZnF), before complex disassembly via the Zpr1 co-chaperone Aim29 and GTP hydrolysis. The eEF1A nucleotide exchange factor eEF1B promotes GDP dissociation. GTP-bound eEF1A can then associate with charged tRNAs for delivery to ribosomes for translation elongation. See “Discussion” for further details. Cartoon templates have been used in our previous work11,12.
