Method for producing polyisoprenoid by reaction catalyzed by mutant cis-prenyltransferase (CPT) family protein, and method for producing rubber product

A method for producing a pneumatic tire, the method comprising:

• producing a polyisoprenoid by binding a cis-prenyltransferase comprising at least 95% sequence identity to the polypeptide of SEQ ID NO:
• 7 or 8 to a Nogo-B receptor (NgBR) in vitro, wherein the NgBR receptor is integrated in a membrane of a rubber particle, thereby producing said polyisoprenoid, and wherein the cys-prenyltransferase catalyzes a cis-chain elongation reaction of an isoprenoid compound;
• kneading the polyisoprenoid with an additive to obtain a kneaded mixture;
• building a green tire from the kneaded mixture;
• and
• vulcanizing the green tire.

A method for producing a rubber product, the method comprising:

• producing a polyisoprenoid by binding a cis-prenyltransferase comprising at least 95% sequence identity to the polypeptide of SEQ ID NO:
• 7 or 8 to a Nogo-B receptor (NgBR) in vitro, wherein the NgBR receptor is integrated in a membrane of a rubber particle, thereby producing said polyisoprenoid, and wherein the cys-prenyltransferase catalyzes a cis-chain elongation reaction of an isoprenoid compound;
• kneading the polyisoprenoid with an additive to obtain a kneaded mixture;
• forming a raw rubber product from the kneaded mixture;
• and
• vulcanizing the raw rubber product.