Abstract
We purified a geranylgeranylglyceryl phosphate (GGGP) synthase from Thermoplasma acidophilum by several steps of chromatography. Based on the proteinase-fragment-mass-pattern analysis of the SDS-PAGE band of the partially purified pro-tein, the DNA sequence encoding the protein was identified from the whole genome sequence database of the species. The gene encoding GGGP synthase in T. acido-philum was cloned after PCR amplification of the gene from the genomic DNA. The recombinant enzyme was expressed in Escherichia coli and purified. A single band with a molecular mass of 27 kDa was obtained by SDS-PAGE analysis. The apparent native molecular mass of the enzyme was about 50 kDa based on gel filtration chro-matography, suggesting that the enzyme is active as a homodimer. As the GGGP syn-thase from Methanobacterium thermoautotrophicum has been reported as a pen-tamer, the enzymes of the two organisms have different oligomeric structures. Other characteristics, including substrate specificity, are similar for the GGGPs of these organisms.
