The genomes of several nonphotosynthetic bacteria, such as
Bacillus subtilis
, and some Archaea include genes for proteins with sequence homology to the large subunit of ribulose bisphosphate carboxylase/oxygenase (RuBisCO). We found that such a RuBisCO-like protein (RLP) from
B. subtilis
catalyzed the 2,3-diketo-5-methylthiopentyl-1-phosphate enolase reaction in the methionine salvage pathway. A growth-defective mutant, in which the gene for this RLP had been disrupted, was rescued by the gene for RuBisCOfrom the photosynthetic bacterium
Rhodospirillum rubrum
. Thus, the photosynthetic RuBisCO from
R. rubrum
retains the ability to function in the methionine salvage pathway in
B. subtilis
.
几种非光合细菌的基因组(如枯草杆菌等)和一些古菌包括具有与核酮糖双磷酸羧化/氧化酶(RuBisCO)大亚基序列同源性的蛋白质基因。我们发现,来自枯草杆菌的这种类RuBisCO蛋白质(RLP)在蛋氨酸拯救途径中催化2,3-二酮-5-甲基硫代戊糖-1-磷酸烯醇酶反应。一个生长缺陷突变体,其中这个RLP基因已被破坏,被光合细菌红螺菌的RuBisCO基因所拯救。因此,来自红螺菌的光合RuBisCO在枯草杆菌中保留了在蛋氨酸拯救途径中发挥作用的能力。