A Gene Cluster for the Mevalonate Pathway from Streptomyces sp. Strain CL190

Abstract

ABSTRACT A biosynthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.34 ), the rate-limiting enzyme of the mevalonate pathway for isopentenyl diphosphate biosynthesis, had previously been purified from Streptomyces sp. strain CL190 and its corresponding gene ( hmgr ) had been cloned (S. Takahashi, T. Kuzuyama, and H. Seto, J. Bacteriol. 181:1256–1263, 1999). Sequence analysis of the flanking regions of the hmgr gene revealed five new open reading frames, orfA to - E , which showed similarity to those encoding eucaryotic and archaebacterial enzymes for the mevalonate pathway. Feeding experiments with [1- 13 C]acetate demonstrated that Escherichia coli JM109 harboring the hmgr gene and these open reading frames used the mevalonate pathway under induction with isopropyl β- d -thiogalactopyranoside. This transformant could grow in the presence of fosmidomycin, a potent and specific inhibitor of the nonmevalonate pathway, indicating that the mevalonate pathway, intrinsically absent in E. coli , is operating in the E. coli transformant. The hmgr gene and orfABCDE are thus unambiguously shown to be responsible for the mevalonate pathway and to form a gene cluster in the genome of Streptomyces sp. strain CL190.