A negative-sense RNA genome
The complete sequencing of the PPR virus genome was achieved in 2005. Its RNA consists of a chain of 15 948 nucleotides. This is one of the longest genomes of the Morbillivirus genus. That of rinderpest has 15 882 nucleotides.
It follows the "rule of six", as do all of the viruses in its genus.
All of the morbilliviruses share the same genome organization.
Their RNA is unsegmented. It presents itself as a single molecule made up of a sequence of 6 non-overlapping genetic units (transcription units). Each unit begins with a start signal followed by a coding sequence, and ends with a stop signal. They are separated by intergenic non coding sequences of 3 nucleotides.
The RNA is said to be negative-sense because it cannot be translated directly into protein. During viral multiplication each gene is first be transcripted into a messenger RNA by the viral polymerase L, then translated into a viral protein by the enzymatic machinery of the host cell.
