Petrovicet al., Science 376 , eabm9798 (2022) 10 June 2022 6of18
Fig. 4. Structural and biochemical analyses of the Nup188-Nup145N interac-
tion.(A) Domain structures ofC. thermophilumNup188, Nic96, and Nup145N and
the effect of each five-alanine substitution on Nup145N binding to Nup188NTD,as
assessed by SEC and indicated by colored boxes above the Nup145N primary
sequence. (B) Summary of SEC binding analysisidentifying the minimal Nup145NR2
(red) region sufficient for binding to Nup188NTD. +++, no effect; ++, weak effect;
+, moderate effect;–, abolished binding. (C) Cartoon representation of the 2.8-Å
C. thermophilumNup188•Nic96R2•Nup145NR2single-particle cryo-EM structure.
Inset indicates region magnified to illustrate molecular details of the Nup188-
Nup145NR2interaction. Red circles indicate residues involved in the Nup188-
Nup145NR2interaction. (D) Effect of Nup145N alanine substitutions (cyan squares)
on Nup188NTDbinding, assayed by SEC (left). Effect of structure-guided Nup188NTD
alanine substitutions on SUMO-Nup145NR2binding, assayed by SEC (right).
(E) KDs determined by triplicate ITC experiments, with the mean and associated
standard error reported. (F) SEC-MALS analysis of Nup188•SUMO-Nic96R2•Nup145N
and Nup188•SUMO-Nic96R2•SUMO-Nup145NR2complex formation and disruption
by mutants. Measured molecular masses areindicated, with respective theoretical
masses provided in parentheses.RESEARCH | STRUCTURE OF THE NUCLEAR PORE