Primary structure of a chitinase-encoding gene (chi1) from the filamentous fungus Aphanocladium album: similarity to bacterial chitinases

Chitinase 1 (Chil) is the major extracellular chitinase from the hyperparasitic fungus, Aphanocladium album. We determined the complete sequence of the chromosomal and cDNA copies of the structural gene (chi1) coding for Chil. The coding region is interrupted by three short introns (55, 53 and 49 bp long). Chil is 423 aa long and begins with a stretch of 34 aa not found in the mature protein. The Chil sequence presents overall similarities with bacterial chitinases from Serratia marcescens and Bacillus circulans. Compared with other chitinases, A. album Chi1 has only two short similarity regions (12 and 8 aa long), which are also found in bacterial, yeast and some plant chitinases.