The reductive carboxylation activity of heterotetrameric pyruvate synthases from hyperthermophilic archaea

Lu Xiao; Guoxia Liu; Fuyu Gong; Zhen Cai; Yin Li

doi:10.1016/j.bbrc.2021.07.091

The reductive carboxylation activity of heterotetrameric pyruvate synthases from hyperthermophilic archaea

Biochem Biophys Res Commun. 2021 Oct 1:572:151-156. doi: 10.1016/j.bbrc.2021.07.091. Epub 2021 Jul 30.

Authors

Lu Xiao¹, Guoxia Liu², Fuyu Gong², Zhen Cai², Yin Li³

Affiliations

¹ CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
² CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
³ CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China. Electronic address: yli@im.ac.cn.

PMID: 34364295
DOI: 10.1016/j.bbrc.2021.07.091

Abstract

Pyruvate synthase (pyruvate:ferredoxin oxidoreductase, PFOR) catalyzes the interconversion of acetyl-CoA and pyruvate, but the reductive carboxylation activities of heterotetrameric PFORs remain largely unknown. In this study, we cloned, expressed, and purified selected six heterotetrameric PFORs from hyperthermophilic archaea. The reductive carboxylation activities of these heterotetrameric PFORs were measured at 70 °C and the ratio of reductive carboxylation activity to oxidative decarboxylation activity (red/ox ratio) were calculated. Four out of six showed reductive decarboxylation activities. Among them, the PFOR_pfm from Pyrolobus fumarii showed the highest reductive carboxylation activities and the highest red/ox ratio, which were 54.32 mU/mg and 0.51, respectively. The divergence of the reductive carboxylation activities and the red/ox ratios of heterotetrameric PFORs in hyperthermophilic archaea indicate the diversity of the functions of PFOR over long-term evolution. This can help us better understand the autotrophic CO₂ fixation process in thermal vent, or in other CO₂-rich high temperature habitat.

Keywords: Anaerobic; CO(2)-fixing enzyme; Ferredoxin; Oxidoreductase; Pyruvate synthase.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Archaea / enzymology*
Carboxylic Acids / metabolism
Oxidation-Reduction
Pyruvate Synthase / metabolism*

Substances

Carboxylic Acids
Pyruvate Synthase