PURIFICATION AND CHARACTERIZATION OF BACTERIAL PHAGE PHI29 GENE 6 PROTEIN.

摘要

A DNA fragment containing the coding region for gene 6 of Bacterial phage ϕ29 was placed into an expression vector. The ϕ29 gene 6 protein was isolated in large amounts by chromatography on double-stranded DNA cellulose and DE52 cellulose. The ϕ29 gene 6 protein was determined to be greater 95% pure and has a molecular weight of approximately 16,000. The ϕ29 gene 6 protein is thought to be a dimer in its native form. The partial N-terminal amino acid sequence of the purified protein is identically to the inferred amino acid sequence from the nucleotide sequence of ϕ29 gene 6. Gene 6 protein of ϕ29 aggregates in a more purified state which suggest protein to protein interactions. Purified gene 6 protein did not stimulate the ϕ29 in vitro DNA replication system and may require binding with other replication proteins to enable it to function. Gene 6 protein binds weakly to double-stranded and single-strand DNA cellulose. There is segmental amino acid sequence and secondary structure homology with adenovirus DNA binding protein Antibody to gene 6 protein inhibits it from binding to ϕ29 DNA. The results presented in this dissertation suggest that ϕ29 gene 6 protein is a weak DNA bind protein and may not be required for the in vitro ϕ29 DNA replication system.