4L8R: Structure of mrna stem-loop, human stem-loop binding protein and 3'hexo ternary complex

Metazoan replication-dependent histone messenger RNAs (mRNAs) have a conserved stem-loop (SL) at their 3'-end. The stem-loop binding protein (SLBP) specifically recognizes the SL to regulate histone mRNA metabolism, and the 3'-5' exonuclease 3'hExo trims its 3'-end after processing. We report the crystal structure of a ternary complex of human SLBP RNA binding domain, human 3'hExo, and a 26-nucleotide SL RNA. Only one base of the SL is recognized specifically by SLBP, and the two proteins primarily recognize the shape of the RNA. SLBP and 3'hExo have no direct contact with each other, and induced structural changes in the loop of the SL mediate their cooperative binding. The 3' flanking sequence is positioned in the 3'hExo active site, but the ternary complex limits the extent of trimming.
PDB ID: 4L8RDownload
MMDB ID: 156321
PDB Deposition Date: 2013/6/17
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.6  Å
Source Organism:
Homo sapiens
Similar Structures:
Biological Unit for 4L8R: trimeric; determined by software (PISA)
Molecular Components in 4L8R
Label Count Molecule
Proteins (2 molecules)
3'-5' Exoribonuclease 1(Gene symbol: ERI1)
Molecule annotation
Histone RNA Hairpin-binding Protein(Gene symbol: SLBP)
Molecule annotation
Nucleotide(1 molecule)
Histone mRNA Stem-loop
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB