The A* protein of phi X174 is an inhibitor of DNA replication.
AUTOR(ES)
Eisenberg, S
RESUMO
Extracts prepared from phi X174 infected E. coli cells inhibited in vitro RF replication The inhibition was dependent upon the presence of A* protein in the reaction and served as an assay to highly purify the A* protein. Purified A* protein bound tightly to duplex DNA as well as single-stranded DNA. The binding of the A* protein to duplex DNA inhibited (I) its single-stranded DNA specific endonucleolytic activity; (II) in vitro synthesis of viral (+) single stranded DNA on an A-RFII DNA complex template; (III) ATP hydrolysis by rep protein and unwinding of the strands of RF DNA. We propose that this inhibitory activity is responsible in vivo for the shut off of E. coli chromosome replication during phi X174 infection, and has a role in the transition from semiconservative RF DNA replication to single-stranded DNA synthesis in the life cycle of phi X174.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=326818Documentos Relacionados
- Enzymatic properties of the bacteriophage phi X174 A protein on superhelical phi X174 DNA: a model for the termination of the rolling circle DNA replication.
- The nuclease specificity of the bacteriophage phi X174 A* protein.
- Conservation of the primosome in successive stages of phi X174 DNA replication.
- Cleavage and circularization of single-stranded DNA: a novel enzymatic activity of phi X174 A* protein.
- Expression of the cloned bacteriophage phi X174 A* gene in Escherichia coli inhibits DNA replication and cell division.