3zj1
Structure of Nab2p tandem zinc finger 12Structure of Nab2p tandem zinc finger 12
Structural highlights
Function[NAB2_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 PubMedThe seven C-terminal CCCH-type zinc fingers of Nab2p bind the poly(A) tail of mRNA ( approximately A25). Using NMR, we demonstrated that the first four (Zf1-Zf4) contain two structurally independent tandems (TZF12 and TZF34) and bind A12 with moderate affinity (KD = 2.3 muM). Nab2p TZF12 contains a long alpha helix that contacts the zinc fingers Zf1 and Zf2 to arrange them similarly to Zf6-7 in the Nab2p Zf5-7 structure. Nab2p TZF34 exhibits a distinctive two-fold symmetry of the zinc centers with mutual recognition of histidine ligands. Our mutagenesis and NMR data demonstrate that the alpha helix of TZF12 and Zf3 of TZF34 define the RNA-binding interface, while Zf1, Zf2, and Zf4 seem to be excluded. These results further our understanding of polyadenosine RNA recognition by the CCCH domain of Nab2p. Moreover, we describe a hypothetical mechanism for controlling poly(A) tail length with specific roles for TZF12, TZF34, and Zf5-7 domains. Two Singular Types of CCCH Tandem Zinc Finger in Nab2p Contribute to Polyadenosine RNA Recognition.,Martinez-Lumbreras S, Santiveri CM, Mirassou Y, Zorrilla S, Perez-Canadillas JM Structure. 2013 Aug 28. pii: S0969-2126(13)00269-4. doi:, 10.1016/j.str.2013.07.019. PMID:23994011[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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