title: Identification of an actin-like protein and of its messenger ribonucleic acid in Saccharomyces cerevisiae.
abstract: We have identified a yeast protein that resembles actins from other eucaryotes in its tight binding to pancreatic deoxyribonuclease I, its copolymerizaton with purified muscle actin, its one-dimensional peptide map, and its apparent polymerization into 7-nm filaments. The yeast actin-like protein yielded a single spot on two-dimensional polyacrylamide gel electrophoresis, suggesting that a single protein species was present. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the actin-like protein had an apparent molecular weight of 45,000 compared with 42,000 for muscle actin. In an attempt to identify the messenger ribonucleic acid coding for the actin-like protein, yeast polyadenylic acid-rich ribonucleic acid was translated in wheat germ and reticulocyte cell-free protein-synthesizing systems. The actin-like protein was identified among the translation products of the reticulocyte system by its tight binding to deoxyribonuclease I, its comigration with the in vivo-synthesized actin-like protein during sodium dodecyl sulfate-polyacrylamide gel electrophoresis, an the similarity of its peptide map to that of the in vivo-synthesized protein. A yeast protein synthesized in the wheat-germ system was also found to bind to deoxyribonuclease I and to copolymerize with muscle actin. However, its apparent molecular weight was about 35,000, suggesting that it was a product either of incomplete translation or of proteolytic cleavage of the actin-like protein.
mesh_terms: D000199:Actins / Q000032:analysis* / Q000096:biosynthesis; D005656:Fungal Proteins / Q000032:analysis* / Q000096:biosynthesis; D008970:Molecular Weight; D014176:Protein Biosynthesis; D012331:RNA, Fungal / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000032:analysis* / Q000235:genetics
chemical_list: D000199:Actins; D005656:Fungal Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger