Scientific Reports (Nov 2021)

Structural insights into bifunctional thaumarchaeal crotonyl-CoA hydratase and 3-hydroxypropionyl-CoA dehydratase from Nitrosopumilus maritimus

  • Ebru Destan,
  • Busra Yuksel,
  • Bradley B. Tolar,
  • Esra Ayan,
  • Sam Deutsch,
  • Yasuo Yoshikuni,
  • Soichi Wakatsuki,
  • Christopher A. Francis,
  • Hasan DeMirci

DOI
https://doi.org/10.1038/s41598-021-02180-8
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 11

Abstract

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Abstract The ammonia-oxidizing thaumarchaeal 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) cycle is one of the most energy-efficient CO2 fixation cycles discovered thus far. The protein encoded by Nmar_1308 (from Nitrosopumilus maritimus SCM1) is a promiscuous enzyme that catalyzes two essential reactions within the thaumarchaeal 3HP/4HB cycle, functioning as both a crotonyl-CoA hydratase (CCAH) and 3-hydroxypropionyl-CoA dehydratase (3HPD). In performing both hydratase and dehydratase activities, Nmar_1308 reduces the total number of enzymes necessary for CO2 fixation in Thaumarchaeota, reducing the overall cost for biosynthesis. Here, we present the first high-resolution crystal structure of this bifunctional enzyme with key catalytic residues in the thaumarchaeal 3HP/4HB pathway.