The role of the Brr5/Ysh1 C-terminal domain and its homolog Syc1 in mRNA 3'-end processing in Saccharomyces cerevisiae.

The cleavage/polyadenylation factor (CPF) of Saccharomyces cerevisiae is thought to provide the catalytic activities of the mRNA 3'-end processing machinery, which include endonucleolytic cleavage at the poly(A) site, followed by synthesis of an adenosine polymer onto the new 3'-end by the CPF subunit Pap1. Because of similarity to other nucleases in the metallo-beta-lactamase family, the Brr5/Ysh1 subunit has been proposed to be the endonuclease. The C-terminal domain of Brr5 lies outside of beta-lactamase homology, and its function has not been elucidated.

Isolation, characterization, and localization of beta-tubulin genomic clones of three Drosophila montium subgroup species.

Genomic libraries were constructed from three Drosophila species, namely Drosophila auraria, Drosophila serrata, and Drosophila kikkawai, belonging to the Drosophila montium subgroup of the Drosophila melanogaster species group. Clones containing beta-tubulin specific sequences were isolated, characterized by restriction endonuclease digestions and Southern hybridizations, and mapped by in situ hybridization on the polytene chromosomes of the species studied. The distribution of the beta-tubulin loci was found to be similar in D.