Regulation of the high-specificity Rubisco genes by the third CbbR-type regulator in a hydrogen-oxidizing bacterium Hydrogenovibriomarinus

Koichi Toyoda; Yoichi Yoshizawa; Masaharu Ishii; Hiroyuki Arai

doi:10.1016/j.jbiosc.2022.09.003

Regulation of the high-specificity Rubisco genes by the third CbbR-type regulator in a hydrogen-oxidizing bacterium Hydrogenovibriomarinus

J Biosci Bioeng. 2022 Dec;134(6):496-500. doi: 10.1016/j.jbiosc.2022.09.003. Epub 2022 Sep 29.

Authors

Koichi Toyoda¹, Yoichi Yoshizawa¹, Masaharu Ishii², Hiroyuki Arai³

Affiliations

¹ Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
² Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
³ Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. Electronic address: aharai@g.ecc.u-tokyo.ac.jp.

PMID: 36182634
DOI: 10.1016/j.jbiosc.2022.09.003

Abstract

The obligate chemolithoautotrophic bacterium, Hydrogenovibrio marinus MH-110, has three ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) isoenzymes, CbbM, CbbLS-1, and CbbLS-2, which differ in CO₂/O₂ specificity factor values. Expressions of CbbM and CbbLS-1 are regulated differently by transcriptional regulators of the LysR family, CbbRm and CbbR1, respectively. CbbLS-2 has the highest specificity and is induced under low CO₂ conditions, but the regulator for the cbbL2S2 genes encoding CbbLS-2 remains unidentified. In this study, the cbbR2 gene encoding the third CbbR-type regulator was identified in the downstream region of the cbbL2S2 and carboxysome gene cluster via transposon mutagenesis. CO₂ depletion induced the cbbR2 gene. The cbbR2 knockout mutant could not grow under low CO₂ conditions and did not produce CbbLS-2. Recombinant CbbR2 protein was bound to the promoter region of the cbbL2S2 genes. These results indicate that CbbR2 is the specific regulator for CbbLS-2 expression.

Keywords: Calvin–Benson–Bassham cycle; Carbon dioxide fixation; Carboxysome; CbbR; Hydrogen-oxidizing bacterium; Hydrogenovibrio marinus; Ribulose-1,5-bisphosphate carboxylase/oxygenase.

MeSH terms

Carbon Dioxide
Hydrogen*
Ribulose-Bisphosphate Carboxylase* / genetics

Substances

Hydrogen
Ribulose-Bisphosphate Carboxylase
Carbon Dioxide