Three proteins of the U7-specific Sm ring function as the molecular ruler to determine the site of 3'-end processing in mammalian histone pre-mRNA.

ABSTRACT: Cleavage of histone pre-mRNAs at the 3' end is guided by the U7 snRNP, which is a component of a larger 3'-end processing complex. To identify other components of this complex, we isolated proteins that stably associate with a fragment of histone pre-mRNA containing all necessary processing elements and a biotin affinity tag at the 5' end. Among the isolated proteins, we identified three well-characterized processing factors: the stem-loop binding protein (SLBP), which interacts with the stem-loop structure upstream of the cleavage site, and both Lsm11 and SmB, which are components of the U7-specific Sm ring. We also identified 3'hExo/Eri-1, a multifunctional 3' exonuclease that is known to trim the 3' end of 5.8S rRNA. 3'hExo primarily binds to the downstream portion of the stem-loop stru

SUBMITTER: Yang XC 

PROVIDER: S-EPMC2715809 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature