title: Molecular mechanisms for the regulation of histone mRNA stem-loop-binding protein by phosphorylation.
abstract: Replication-dependent histone mRNAs end with a conserved stem loop that is recognized by stem-loop-binding protein (SLBP). The minimal RNA-processing domain of SLBP is phosphorylated at an internal threonine, and Drosophila SLBP (dSLBP) also is phosphorylated at four serines in its 18-aa C-terminal tail. We show that phosphorylation of dSLBP increases RNA-binding affinity dramatically, and we use structural and biophysical analyses of dSLBP and a crystal structure of human SLBP phosphorylated on the internal threonine to understand the striking improvement in RNA binding. Together these results suggest that, although the C-terminal tail of dSLBP does not contact the RNA, phosphorylation of the tail promotes SLBP conformations competent for RNA binding and thereby appears to reduce the entropic penalty for the association. Increased negative charge in this C-terminal tail balances positively charged residues, allowing a more compact ensemble of structures in the absence of RNA.
authors.affiliation: Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709;
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027;
authors.forename: Dazhi
authors.initials: D
authors.lastname: Tan
authors.affiliation: Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709;
authors.forename: Eugene F
authors.initials: EF
authors.lastname: DeRose
authors.affiliation: Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709;
authors.forename: Lalith
authors.initials: L
authors.lastname: Perera
authors.affiliation: Department of Biochemistry and Biophysics andIntegrative Program in Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Dominski
authors.affiliation: Department of Biochemistry and Biophysics andIntegrative Program in Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599 marzluff@med.unc.edu ltong@columbia.edu hall4@niehs.nih.gov.
authors.forename: William F
authors.initials: WF
authors.lastname: Marzluff
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027; marzluff@med.unc.edu ltong@columbia.edu hall4@niehs.nih.gov.
authors.forename: Liang
authors.initials: L
authors.lastname: Tong
authors.affiliation: Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709; marzluff@med.unc.edu ltong@columbia.edu hall4@niehs.nih.gov.
authors.forename: Traci M Tanaka
authors.initials: TM
authors.lastname: Hall
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002151:Calorimetry; D018360:Crystallography, X-Ray; D029721:Drosophila Proteins / Q000737:chemistry / Q000378:metabolism*; D004331:Drosophila melanogaster; D019277:Entropy; D031541:Fluorescence Resonance Energy Transfer; D006657:Histones / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D039221:mRNA Cleavage and Polyadenylation Factors / Q000737:chemistry / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D006657:Histones; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C490155:SLBP protein, Drosophila; C092663:SLBP protein, human; D039221:mRNA Cleavage and Polyadenylation Factors
keywords: NMR; X-ray crystallography; intrinsically disordered protein