2lhn
From Proteopedia
RNA-binding zinc finger protein
Structural highlights
FunctionNAB2_YEAST This essential protein binds to polyadenylated RNA and single-stranded DNA. It may be involved not only in RNA processing but also in transcription regulation. Believed to associate directly with nascent RNA polymerase II transcripts and remain associated during subsequent nuclear RNA processing reactions. Publication Abstract from PubMedPolyadenylation regulation and efficient nuclear export of mature mRNPs both require the polyadenosine-RNA-binding protein, Nab2, which contains seven CCCH Zn fingers. We describe here the solution structure of fingers 5-7, which are necessary and sufficient for high-affinity polyadenosine-RNA binding, and identify key residues involved. These Zn fingers form a single structural unit. Structural coherence is lost in the RNA-binding compromised Nab2-C437S mutant, which also suppresses the rat8-2 allele of RNA helicase Dbp5. Structure-guided Nab2 variants indicate that dbp5(rat8-2) suppression is more closely linked to hyperadenylation and suppression of mutant alleles of the nuclear RNA export adaptor, Yra1, than to affinity for polyadenosine-RNA. These results indicate that, in addition to modulating polyA tail length, Nab2 has an unanticipated function associated with generating export-competent mRNPs, and that changes within fingers 5-7 lead to suboptimal assembly of mRNP export complexes that are more easily disassembled by Dbp5 upon reaching the cytoplasm. Structural Basis for Polyadenosine-RNA Binding by Nab2 Zn Fingers and Its Function in mRNA Nuclear Export.,Brockmann C, Soucek S, Kuhlmann SI, Mills-Lujan K, Kelly SM, Yang JC, Iglesias N, Stutz F, Corbett AH, Neuhaus D, Stewart M Structure. 2012 Jun 6;20(6):1007-18. Epub 2012 May 3. PMID:22560733[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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