Biodegradable polyester with desired physical properties.A mutant
poly(3-hydroxyalkanoic acid) synthase comprising an amino acid sequence
of (a) or (b) below. (a) A mutant amino acid sequence derived from SEQ ID
No. 1, wherein at least one amino acid selected from the group consisting
of glutamic acid at position 130, serine at position 325, serine at
position 477 and glutamine at position 481 is substituted by another
amino acid. (b) A mutant amino acid sequence derived from SEQ ID No. 1
wherein at least one amino acid selected from the group consisting of
glutamic acid at position 130, serine at position 325, serine at position
477 and glutamine at position 481 is substituted by another amino acid,
wherein at least one amino acid other than the amino acids at positions
130, 325, 477 and 481 is deleted, substituted and/or added, wherein the
mutant amino acid sequence has the activity to biosynthesize
biodegradable polyester.