Journal Article

A RuBisCO-mediated carbon metabolic pathway in methanogenic archaea

Kimura Hiroyuki, Kono Takunari, Ashida Hiroki, Mizohata Eiichi, Mehrotra Sandhya, Endo Chikako, Kizu Natsuko, Hasunuma Tomohisa, Inoue Tsuyoshi, Matusda Mami, Yokota Akiho, Matsumura Hiroyoshi

2017

Overview

Two enzymes are considered to be unique to the photosynthetic Calvin–Benson cycle: ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), responsible for CO 2 fixation, and phosphoribulokinase (PRK). Some archaea possess bona fide RuBisCOs, despite not being photosynthetic organisms, but are thought to lack PRK. Here we demonstrate the existence in methanogenic archaea of a carbon metabolic pathway involving RuBisCO and PRK, which we term ‘reductive hexulose-phosphate’ (RHP) pathway. These archaea possess both RuBisCO and a catalytically active PRK whose crystal structure resembles that of photosynthetic bacterial PRK. Capillary electrophoresis-mass spectrometric analysis of metabolites reveals that the RHP pathway, which differs from the Calvin–Benson cycle only in a few steps, is active in vivo . Our work highlights evolutionary and functional links between RuBisCO-mediated carbon metabolic pathways in methanogenic archaea and photosynthetic organisms. Whether the RHP pathway allows for autotrophy (that is, growth exclusively with CO 2 as carbon source) remains unknown. Although not photosynthetic, some archaea possess RuBisCO, one of the enzymes characteristic of the photosynthetic Calvin-Benson cycle, but apparently lack another one, phosphoribulokinase (PRK). Here the authors describe a carbon metabolic pathway in methanogenic archaea, involving RuBisCO and PRK.

• Publisher: Nature Publishing Group,Nature Publishing Group UK,Nature Portfolio
• Subject: 631/326/26/2523 / 631/45/607 / 631/535/1266 / 631/92/1643 / 82/80 / 82/83 / Archaeal Proteins - chemistry / Archaeal Proteins - genetics / Archaeal Proteins - metabolism / Carbon / Carbon - metabolism / Carbon dioxide fixation / Carbon sources / Crystal structure / Enzymes / Euryarchaeota - classification / Euryarchaeota - enzymology / Euryarchaeota - genetics / Euryarchaeota - metabolism / Humanities and Social Sciences / Kinases / Metabolic Networks and Pathways / Metabolism / Metabolites / multidisciplinary / Phosphotransferases (Alcohol Group Acceptor) - chemistry / Phosphotransferases (Alcohol Group Acceptor) - genetics / Phosphotransferases (Alcohol Group Acceptor) - metabolism / Photosynthesis / Phylogenetics / Phylogeny / Proteins / Ribulose-Bisphosphate Carboxylase - chemistry / Ribulose-Bisphosphate Carboxylase - genetics / Ribulose-Bisphosphate Carboxylase - metabolism / Science / Science (multidisciplinary)