HYALURONAN SYNTHASE OF CHLORELLA VIRUS PBCV-1

Sequence analysis of the 330-kilobase genome of the virus PBCV-1 that infects a chlorella-like green algae revealed an open reading frame, A 98R, with similarity to several hyaluronan synthases. Hyaluronan is an essential polysaccharide found in higher animals as well as in a few pathogenic bacteria. Expression of the A98R gene product in Escherichi a coli indicated that the recombinant protein is an authentic hyaluron an synthase. A98R is expressed early in PBCV-1 infection and hyalurona n is produced in infected algae. These results demonstrate that a viru s can encode an enzyme capable of synthesizing a carbohydrate polymer and that hyaluronan exists outside of animals and their pathogens.