title: The baculovirus single-stranded DNA binding protein, LEF-3, forms a homotrimer in solution.
abstract: LEF-3 is one of six proteins from Autographa californica multinucleocapsid polyhedrosis virus required for transient DNA replication and has the properties of a single-stranded DNA binding protein. In this report we demonstrate that LEF-3 interacts with itself in both yeast two-hybrid assays and glutathione S-transferase fusion affinity assays. LEF-3 deletion clones which were unable to interact with full-length LEF-3 also failed to support transient DNA replication, suggesting that this interaction is required for the proper function of LEF-3. LEF-3 was purified to homogeneity and characterized by analytical ultracentrifugation and native polyacrylamide gel electrophoresis. These studies revealed that LEF-3 was present as a 132-kDa complex, indicating that its native conformation is that of a homotrimer. This result was confirmed by cross-linking with glutaraldehyde followed by matrix-assisted laser desorption/ionization mass spectrometry.
authors.affiliation: Department of Agricultural Chemistry, Oregon State University, Corvallis 97331-7301, USA.
authors.forename: J T
authors.initials: JT
authors.lastname: Evans
authors.forename: G F
authors.initials: GF
authors.lastname: Rohrmann
mesh_terms: D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D012996:Solutions; D014461:Ultracentrifugation; D014764:Viral Proteins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D004268:DNA-Binding Proteins; D012996:Solutions; D014764:Viral Proteins; C094647:late expression factor 3, baculovirus