Characterization of yeast U1 snRNP A protein: identification of the N-terminal RNA binding domain (RBD) binding site and evidence that the C-terminal RBD functions in splicing.
The yeast U1A protein is a U1 snRNP-specific protein. Like its human counterpart (hU1A), it has two conserved RNA binding domains (RBDs). The N-terminal RBD is quite different from the human protein, and a binding site on yeast U1 snRNA is not readily apparent. The C-terminal RBD is of unknown function. Using in vivo dimethyl sulfate (DMS) protection of mutant strains, we defined a region in yeast U1 snRNA as the likely U1A N-terminal RBD binding site. This was confirmed by direct in vitro binding assays. The site is very different from its vertebrate counterpart, but its location within yeast U1 snRNA suggests a conserved structural relationship to other U1 snRNP components. Genetic studies and sensitive in vivo splicing measurements indicate that the yeast U1A C-terminal RBD also functions in pre-mRNA splicing. We propose that the N-terminal RBD serves to tether the splicing-relevant C-terminal RBD to the snRNP.
Tang
J
J
Howard Hughes Medical Institute and Department of Biology, Brandeis University, Waltham, Massachusetts 02254, USA.
Rosbash
M
M
D000477:Alkylating Agents; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal / Q000235:genetics; D005804:Genes, Lethal / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000378:metabolism; D012326:RNA Splicing / Q000502:physiology*; D012331:RNA, Fungal / Q000737:chemistry / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013463:Sulfuric Acid Esters
D000477:Alkylating Agents; D005656:Fungal Proteins; D012322:RNA Precursors; D012331:RNA, Fungal; D016601:RNA-Binding Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear; D013463:Sulfuric Acid Esters; C075339:U1A protein; C007482:dimethyl sulfate