Patent ID: RE43425

Claim:
A mutant prenyl diphosphate synthase having a modified the amino acid sequence , wherein said mutant prenyl diphosphate synthase comprises an aspartic acid-rich domain having the sequence, D 1 D 2 X 1 X 2 (X 3 X 4 )D 3 , in region II of said mutant prenyl diphosphate synthase, wherein each of D 1 , D 2 and D 3 denote an aspartic acid residue; X 1 , X 2 , X 3 and X 4 are each independently any amino acid and X 3 and X 4 are each optionally independently present in the aspartic acid rich domain, and wherein said mutant prenyl diphosphate synthase comprises (1) at least one amino acid substitution, said at least one amino acid substitution located at at least one ammo acid position selected from (a) an amino acid between D 1 and the amino acid residue at the fifth position upstream of D 1 and (b) the amino acid residue located one amino acid position upstream of D 3 ; (2) at least one additional amino acid inserted between D 3 and the first amino acid upstream of D 3 ; or a combination of (2) and (3); wherein said mutant prenyl diphosphate synthase synthesizes prenyl diphosphate which is shorter than prenyl diphosphate synthesized by a corresponding wild-type enzyme of SEQ ID NO:1, except that: threonine at position 78 of SEQ ID NO:1 is replaced with phenylalanine and histidine at position 81 of SEQ ID NO:1 is replaced with alanine; threonine at position 78 of SEQ ID NO:1 is replaced with phenylalanine and histidine at position 81 of SEQ ID NO:1 is replaced with leucine; phenylalanine at position 77 of SEQ ID NO:1 is replaced with tyrosine, threonine at position 78 of SEQ ID NO:1 is replaced with phenylalanine, and histidine at position 81 of SEQ ID NO:1 is replaced with leucine; phenylalanine at position 77 of SEQ ID NO:1 is replaced with tyrosine, threonine at position 78 of SEQ ID NO:1 is replaced with phenylalanine, and histidine at position 81 of SEQ ID NO:1 is replaced with alanine; or phenylalanine at position 77 of SEQ ID NO:1 is replaced with tyrosine, threonine at position 78 of SEQ ID NO:1 is replaced with serine, valine at position 80 of SEQ ID NO:1 is replaced with isoleucine, isoleucine at position 84 of SEQ ID NO:1 is replaced with leucine, and proline and serine are inserted sequentially between position 84 and position 85 of SEQ ID NO:1 .