PMID: 29020104

Authors:

Aik WS, Lin MH, Tan D, Tripathy A, Marzluff WF, Dominski Z, Chou CY, Tong L

Title:

The N-terminal domains of FLASH and Lsm11 form a 2:1 heterotrimer for histone pre-mRNA 3'-end processing.

Journal:

PLoS One. 2017 Oct 11;12(10):e0186034. doi: 10.1371/journal.pone.0186034., eCollection 2017.

Abstract:

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.