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Publication Abstract from PubMed

Heterodimerization of RNA binding proteins Nrd1 and Nab3 is essential to communicate the RNA recognition in the nascent transcript with the Nrd1 recognition of the Ser5-phosphorylated Rbp1 C-terminal domain in RNA polymerase II. The structure of a Nrd1-Nab3 chimera reveals the basis of heterodimerization, filling a missing gap in knowledge of this system. The free form of the Nrd1 interaction domain of Nab3 (NRID) forms a multi-state three-helix bundle that is clamped in a single conformation upon complex formation with the Nab3 interaction domain of Nrd1 (NAID). The latter domain forms two long helices that wrap around NRID, resulting in an extensive protein-protein interface that would explain the highly favorable free energy of heterodimerization. Mutagenesis of some conserved hydrophobic residues involved in the heterodimerization leads to temperature-sensitive phenotypes, revealing the importance of this interaction in yeast cell fitness. The Nrd1-Nab3 structure resembles the previously reported Rna14/Rna15 heterodimer structure, which is part of the poly(A)-dependent termination pathway, suggesting that both machineries use similar structural solutions despite they share little sequence homology and are potentially evolutionary divergent.

Structural basis of Nrd1-Nab3 heterodimerization.,Chaves-Arquero B, Martinez-Lumbreras S, Camero S, Santiveri CM, Mirassou Y, Campos-Olivas R, Jimenez MA, Calvo O, Perez-Canadillas JM Life Sci Alliance. 2022 Jan 12;5(4). pii: 5/4/e202101252. doi:, 10.26508/lsa.202101252. Print 2022 Apr. PMID:35022249^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.