MUTANT CIS-PRENYLTRANSFERASE (CPT) FAMILY PROTEIN, METHOD FOR PRODUCING POLYISOPRENOID, VECTOR, TRANSGENIC PLANT, METHOD FOR PRODUCING PNEUMATIC TIRE, AND METHOD FOR PRODUCING RUBBER PRODUCT

Provided are a mutant cis-prenyltransferase (CPT) family protein and a method for producing a polyisoprenoid, which enable the production of a high molecular weight polyisoprenoid. Included is a mutant cis-prenyltransferase (CPT) family protein obtained by mutating the amino acid sequence of a C-terminal region of a cis-prenyltransferase (CPT) family protein not found on rubber particles to be identical or similar to the amino acid sequence of a C-terminal region of a cis-prenyltransferase (CPT) family protein found on rubber particles.