Isolation and nucleotide sequence of theThiobacillus ferrooxidans genes for the small and large subunits of ribulose 1,5‐bisphosphate car☐ylase/oxygenase

Abstract

The genes encoding for the large (rbcL) and small (rbcS) subunits of ribulose-1,5-bisphosphate car☐ylase (RuBisCO) were cloned from the obligate autotrophThiobacillus ferrooxidans, a bacterium involved in the bioleaching of minerals. Nucleotide sequence analysis of the cloned DNA showed that the two coding regions are separated by a 30-bp intergenic region, the smallest described for the RuBisCO genes. TherbcL andrbcS genes encode polypeptides of 473 and 118 amino acids, respectively. Comparison of the nucleotide and amino acid sequences with those of the genes forrbcL andrbcS found in other species demonstrated that theT. ferrooxidans genes have the closest degree of identity with those ofChromatium vinosum and ofAlvinoconcha hessleri endosymbiont. BothT. ferrooxidans enzyme subunits contain all the conserved amino acids that are known to participate in the catalytic process or in holoenzyme assembly