This is the Gle2-binding sequence (GLEBS) of Nup98, which forms a hairpin that binds with its C-terminal arm to an essentially invariant hydrophobic surface that extends over the top face of the Rae1 beta-propeller [1]. This interaction is required for Rae1 binding. Rae1-Nup98(GLEBS) form a complex with single-stranded RNA-binding capability that directly binds to the mRNP in several steps of the mRNA export pathway [1-3].

1: Structural and functional analysis of the interaction between the nucleoporin Nup98 and the mRNA export factor Rae1. Ren Y, Seo HS, Blobel G, Hoelz A; Proc Natl Acad Sci U S A. 2010;107:10406-10411. PMID:20498086

2: Vesiculoviral matrix (M) protein occupies nucleic acid binding site at nucleoporin pair (Rae1 * Nup98). Quan B, Seo HS, Blobel G, Ren Y; Proc Natl Acad Sci U S A. 2014;111:9127-9132. PMID:24927547

3: Molecular mechanism underlying selective inhibition of mRNA nuclear export by herpesvirus protein ORF10. Feng H, Tian H, Wang Y, Zhang Q, Lin N, Liu S, Yu Y, Deng H, Gao P; Proc Natl Acad Sci U S A. 2020;117:26719-26727. PMID:33033226