MOLECULAR-CLONING AND NUCLEOTIDE-SEQUENCES OF THE GENES FOR 2 ESSENTIAL PROTEINS CONSTITUTING A NOVEL ENZYME-SYSTEM FOR HEPTAPRENYL DIPHOSPHATE SYNTHESIS
A. Koiketakeshita et al., MOLECULAR-CLONING AND NUCLEOTIDE-SEQUENCES OF THE GENES FOR 2 ESSENTIAL PROTEINS CONSTITUTING A NOVEL ENZYME-SYSTEM FOR HEPTAPRENYL DIPHOSPHATE SYNTHESIS, The Journal of biological chemistry, 270(31), 1995, pp. 18396-18400
The genes encoding two dissociable components essential for Bacillus s
tearothermophilus heptaprenyl diphosphate synthase ans-hexaprenyl-diph
osphate:isopentenyl-diphosphate hexaprenyl-trans-transferase, EC 2.5.1
.30) were cloned, and their nucleotide sequences were determined. Sequ
ence analyses revealed the presence of three open reading frames withi
n 2,350 base pairs, designated as ORF-1, ORF-2, and ORF-3 in order of
nucleotide sequence, which encode proteins of 220, 234, and 323 amino
acids, respectively. Deletion experiments have shown that expression o
f the enzymatic activity requires the presence of ORF-1 and ORF-3, but
ORF-2 is not essential. As a result, this enzyme was proved genetical
ly to consist of two different protein components with molecular masse
s of 25 kDa (Component I) and 36 kDa (Component II), encoded by two of
the three tandem genes. The protein encoded by ORF-1 has no similarit
y to any protein so far registered. However, the protein encoded by OR
F-3 shows a 32% similarity to the farnesyl diphosphate synthase of the
same bacterium and has seven highly conserved regions that have been
shown typical in prenyltransferases (Koyama, T., Obata, S., Osabe, M.,
Takeshita, A., Yokoyama, K., Uchida, M., Nishino, T., and Ogura, K. (
1993) J. Biochem. (Tokyo) 113, 355-363).