Identification, cloning, and functional analysis of the human U6 snRNA-specific terminal uridylyl transferase.

ABSTRACT: Mammalian cells contain a highly specific terminal uridylyl transferase (TUTase) that exclusively accepts U6 snRNA as substrate. This enzyme, termed U6-TUTase, was purified from HeLa cell extracts and analyzed by microsequencing. All sequenced peptides matched a unique human cDNA coding for a previously unknown protein. Domain structure analysis revealed that the U6-TUTase also belongs to the well-characterized poly(A) polymerase protein superfamily. However, by amino acid sequence as well as RNA-binding motifs, human U6-TUTase is highly divergent from both the poly(A) polymerases and from the TUTases identified within the editing complexes of trypanosomes. After cloning, the recombinant U6-TUTase was expressed in HeLa cells. Analysis of its catalytical activity confirmed the identity of t

SUBMITTER: Trippe R 

PROVIDER: S-EPMC1524887 | biostudies-literature | 2006 Aug

REPOSITORIES: biostudies-literature