English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A modified 3-hydroxypropionate cycle has been proposed as the autotrophic CO2 fixation pathway for the thermoacidophilic crenarchaeonMetallosphaera sedula . The cycle requires the reductive conversion of 3-hydroxypropionate to propionyl-coenzyme A (propionyl-CoA). The specific activity of the 3-hydroxypropionate-, CoA-, and MgATP-dependent oxidation of NADPH in autotrophically grown cells was 0.023 μmol min−1 mg protein−1 . The reaction sequence is catalyzed by at least two enzymes. The first enzyme, 3-hydroxypropionyl-CoA synthetase, catalyzes the following reaction: 3-hydroxypropionate + ATP + CoA → 3-hydroxypropionyl-CoA + AMP + PPi . The enzyme was purified 95-fold to a specific activity of 18 μmol min−1 mg protein−1 from autotrophically grownM. sedula cells. An internal peptide sequence was determined and a gene encoding a homologous protein identified in the genome ofSulfolobus tokodaii ; similar genes were found inS. solfataricus andS. acidocaldarius . The gene was heterologously expressed inEscherichia coli , and the His-tagged protein was purified. Both the native enzyme fromM. sedula and the recombinant enzyme fromS. tokodaii not only activated 3-hydroxypropionate to its CoA ester but also activated propionate, acrylate, acetate, and butyrate; however, with the exception of propionate, the affinities for these substrates were reduced. 3-Hydroxypropionyl-CoA synthetase is up-regulated eightfold in autotrophically versus heterotrophically grownM. sedula , supporting its proposed role during CO2 fixation in this archaeon and possibly other members of theSulfolobaceae family.

3-Hydroxypropionyl-Coenzyme A Synthetase from Metallosphaera sedula , an Enzyme Involved in Autotrophic CO 2 Fixation

3-Hydroxypropionyl-Coenzyme A Synthetase from Metallosphaera sedula , an Enzyme Involved in Autotrophic CO ₂ Fixation