DNA of øX174,Genome,ssDNA,Overlapping of Genes,Circular Molecule,Bacteriophage,Nucleotide Sequence

DNA of øX174

	DNA of øX174 - The genome of φX174 consists of a single covalently continuous circular molecule of ssDNA. It does not contain any non DNA components, and is completely degraded by nucleases. The DNA has the same polarity as mRNA, and is thus a (+) strand. The bacteriophage has 9 genes arranged in the order A-B-C-D-E-J-F-G-H which code for 9 proteins.
There is overlapping of genes, and two genes which should normally code for only, two proteins, actually code four. Gene B is completely contained within gene A and genes E within gene D. Sanger and his colleagues have mapped the entire nucleotide sequence of φX174 DNA and have shown that it contains 5,386 nucleotides. (See 'Genes within gene in the chapter on Genes. Vol. I).