Petuvirus

The genus Petuvirus belongs to the family Caulimoviridae and Caulimovirirdae is classified under group VII DNA Reverse Transcribing Viruses. Petuviruses are plant viruses. There genome is unsegmented and monopartite (meaning all genes are found within one segment of nucleic acid), containing a double-stranded DNA molecule that forms an open circle. It sgenome is 7200 nucleotides long and has a guanine + cytosine content of 38.2 %. There are terminally redundant sequences on the genome which have direct terminal repeats that are reiterated internally in inverted form. The virus codes for 2 ORF(s). Viral capsid is unenveloped. Its capsid shells are multilayered. The capsid is round to elongate with icosahedral symmetry and the virus is composed of 16 % nucleic acid. Petuviruses have a buoyant density in CsCl of 1.31 g cm-3 and there are 1 sedimenting component(s) found in purified preparations. The sedimentation coefficient is 218–251.5–285 S20w while the thermal inactivation point (TIP) is at 55–57.5–60°C. Putuviruses including other members of the Caulimovirusus such as soymoviruses and Cavemoviruses form isometric particles whereas members of Badnaviruses and Tungroviruses have bacilliform virus particle Lipids are not reported.