4TUX: Drosophila Stem-loop Binding Protein Complexed With Histone Mrna Stem- Loop

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.
PDB ID: 4TUXDownload
MMDB ID: 121613
PDB Deposition Date: 2014/6/25
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 3.08  Å
Source Organism:
synthetic construct
Similar Structures:
Biological Unit for 4TUX: dimeric; determined by author and by software (PISA)
Molecular Components in 4TUX
Label Count Molecule
Protein (1 molecule)
Histone RNA Hairpin-binding Protein(Gene symbol: Slbp)
Molecule annotation
Nucleotide(1 molecule)
RNA (26-mer)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB