2kjm
From Proteopedia
Solution structure of SLBP RNA binding domain fragment
Structural highlights
Function[SLBP_HUMAN] RNA-binding protein involved in the histone pre-mRNA processing. Binds the stem-loop structure of replication-dependent histone pre-mRNAs and contributes to efficient 3'-end processing by stabilizing the complex between histone pre-mRNA and U7 small nuclear ribonucleoprotein (snRNP), via the histone downstream element (HDE). Plays an important role in targeting mature histone mRNA from the nucleus to the cytoplasm and to the translation machinery. Stabilizes mature histone mRNA and could be involved in cell-cycle regulation of histone gene expression. Involved in the mechanism by which growing oocytes accumulate histone proteins that support early embryogenesis. Binds to the 5' side of the stem-loop structure of histone pre-mRNAs.[1] [2] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn metazoans, the majority of histone proteins are generated from replication-dependent histone mRNAs. These mRNAs are unique in that they are not polyadenylated but have a stem-loop structure in their 3' untranslated region. An early event in 3' end formation of histone mRNAs is the binding of stem-loop binding protein (SLBP) to the stem-loop structure. Here we provide insight into the mechanism by which SLBP contacts the histone mRNA. There are two binding sites in the SLBP RNA binding domain for the histone mRNA hairpin. The first binding site (Glu129-Val158) consists of a helix-turn-helix motif that likely recognizes the unpaired uridines in the loop of the histone hairpin and, upon binding, destabilizes the first G-C base pair at the base of the stem. The second binding site lies between residues Arg180 and Pro200, which appears to recognize the second G-C base pair from the base of the stem and possibly regions flanking the stem-loop structure. We show that the SLBP-histone mRNA complex is regulated by threonine phosphorylation and proline isomerization in a conserved TPNK sequence that lies between the two binding sites. Threonine phosphorylation increases the affinity of SLBP for histone mRNA by slowing the off rate for complex dissociation, whereas the adjacent proline acts as a critical hinge that may orient the second binding site for formation of a stable SLBP-histone mRNA complex. The nuclear magnetic resonance and kinetic studies presented here provide a framework for understanding how SLBP recognizes histone mRNA and highlight possible structural roles of phosphorylation and proline isomerization in RNA binding proteins in remodeling ribonucleoprotein complexes. Interaction of the histone mRNA hairpin with stem-loop binding protein (SLBP) and regulation of the SLBP-RNA complex by phosphorylation and proline isomerization.,Zhang M, Lam TT, Tonelli M, Marzluff WF, Thapar R Biochemistry. 2012 Apr 17;51(15):3215-31. Epub 2012 Apr 3. PMID:22439849[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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