A Schizosaccharomyces pombe homologue, Psi, was cloned from Schizosaccharomyces pombe cDNA library. Deduced amino acid sequence of the cDNA has 55% sequence homology with the Saccharomyces cerevisiae Sis1 protein and contains the structural features of a family of DnaJ proteins. This homology suggests Psi protein may be implicated in the initiation of translation as like Sis1 function of Saccharomyces cerevisiae.