Characterization of a chitinase gene encoded by virus-sensitive chlorella strains and expressed during virus infection

A chitinase gene [hChti-1] was found and characterized in a few strains of Chlorella species that are sensitive to Chlorella viruses. A cDNA clone of hChti-1 obtained from Chlorella strain NC64A contained a 401 aa [1206 bp] open reading frame, whose amino acid sequence was most similar to that of family 18 catalytic domain I of dual-structured chitinase vChti-1 encoded by Chlorella virus CVK2. The expression of hChti-1 was induced by virus infection and functional chitinase protein was produced. Since the hChti-1 gene was strictly limited to virus-sensitive strains, its occurrence seems to be involved in the virus infection mechanism. This is the first report of chitinase encoded and produced by unicellular algae