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Enzymatic properties of the bacteriophage φX174 A * protein on superhelical φX174 DNA: a model for the termination of the rolling circle DNA replication

1981; Oxford University Press; Volume: 9; Issue: 9 Linguagem: Inglês

10.1093/nar/9.9.2037

1362-4962

Arie van der Ende, S.A. Langeveld, Renske Teertstra, G.A. van Arkel, Peter Weisbeek,

DNA Repair Mechanisms

Incubation of phi X174 replication form I DNA with the A* protein of phi X174 in the presence of MN2+ results in the formation of three different types of DNA molecules: open circular form DNA (RFII), linear form DNA (RFIII) and the relaxed covalently closed form DNA (RFIV). The RFII and RFIII DNAs are shown to be A* protein-DNA complexes by electron microscopy using the protein labeling technique of Wu and Davidson (1). The linear double-stranded RFIII DNA molecule carries at one end a covalently attached A* protein whereas at the other end of the molecule the single-stranded termini are covalently linked to each other. The structure of the RFIII DNA shows its way of formation. The described properties of the A* protein indicate the way the larger A protein functions in the termination step of the rolling-circle type of phi X174 DNA replication.