The EntD-like phosphopantetheinyl transferase (PPTase) gene, cloned from the eicosapentaenoic acid-producing bacterium Photobacterium profundum strain SS9, has an ORF of 690 bp encoding a 230-amino acid protein. When this PPTase gene was expressed in Escherichia coli with pfaA, pfaB, pfaC and pfaD derived from Moritella marina MP-1, which were four of five essential genes for biosynthesis of docosahexaenoic acid (DHA), the DHA production of the recombinant was 2% (w/w) of total fatty acids. This is the first report showing that the EntD-like PPTase is involved in producing n-3 polyunsaturated fatty acids.