The N-terminal domains of FLASH and Lsm11 form a 2:1 heterotrimer for histone pre-mRNA 3'-end processing.
Publication Type:Journal Article
Source:PLoS One, Volume 12, Issue 10, p.e0186034 (2017)
Keywords:Amino Acid Sequence, Biophysical Phenomena, Carrier Proteins, Chromatography, Gel, Crystallography, X-Ray, Cysteine, Histones, Light, Mutation, Protein Binding, Protein Domains, Protein Multimerization, Protein Structure, Secondary, RNA Precursors, RNA Processing, Post-Transcriptional, RNA-Binding Proteins, Scattering, Radiation, Sequence Alignment, Ultracentrifugation
<p>Unlike canonical pre-mRNAs, animal replication-dependent histone pre-mRNAs lack introns and are processed at the 3'-end by a mechanism distinct from cleavage and polyadenylation. They have a 3' stem loop and histone downstream element (HDE) that are recognized by stem-loop binding protein (SLBP) and U7 snRNP, respectively. The N-terminal domain (NTD) of Lsm11, a component of U7 snRNP, interacts with FLASH NTD and these two proteins recruit the histone cleavage complex containing the CPSF-73 endonuclease for the cleavage reaction. Here, we determined crystal structures of FLASH NTD and found that it forms a coiled-coil dimer. Using solution light scattering, we characterized the stoichiometry of the FLASH NTD-Lsm11 NTD complex and found that it is a 2:1 heterotrimer, which is supported by observations from analytical ultracentrifugation and crosslinking.</p>