Malonyl-coenzyme A reductase in the modified 3-hydroxypropionate cycle for autotrophic carbon fixation in archaeal Metallosphaera and Sulfolobus spp.

ABSTRACT: Autotrophic members of the Sulfolobales (Crenarchaeota) contain acetyl-coenzyme A (CoA)/propionyl-CoA carboxylase as the CO2 fixation enzyme and use a modified 3-hydroxypropionate cycle to assimilate CO2 into cell material. In this central metabolic pathway malonyl-CoA, the product of acetyl-CoA carboxylation, is further reduced to 3-hydroxypropionate. Extracts of Metallosphaera sedula contained NADPH-specific malonyl-CoA reductase activity that was 10-fold up-regulated under autotrophic growth conditions. Malonyl-CoA reductase was partially purified and studied. Based on N-terminal amino acid sequencing the corresponding gene was identified in the genome of the closely related crenarchaeum Sulfolobus tokodaii. The Sulfolobus gene was cloned and heterologously expressed in Escherichia coli

SUBMITTER: Alber B 

PROVIDER: S-EPMC1698253 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature