Article
Microbiology
Brenda S. Pratte, Teresa Thiel
Summary: This study identified unique and overlapping functions of two homologous transcriptional activators, CnfR1 and CnfR2, in regulating two distinct nitrogenase systems in Anabaena variabilis. CnfR1 was found to be promiscuous in activating both nitrogenase systems, while CnfR2 relied on additional cellular factors to activate only one nitrogenase system.
MICROBIOLOGY SPECTRUM
(2021)
Article
Biochemistry & Molecular Biology
Leland B. Gee, Aubrey D. Scott, Christie H. Dapper, William E. Newton, Stephen P. Cramer
Summary: This study investigated the interaction of CO with the alpha-R277H variant of the Azotobacter vinelandii N2ase MoFe protein. It was found that multiple CO-inhibited forms were formed with the variant at different pH values, indicating the involvement of protonation/deprotonation.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2022)
Review
Biochemistry & Molecular Biology
Julia S. Martin del Campo, Jack Rigsbee, Marcelo Bueno Batista, Florence Mus, Luis M. Rubio, Oliver Einsle, John W. Peters, Ray Dixon, Dennis R. Dean, Patricia C. Dos Santos
Summary: Understanding the reduction of nitrogen gas to ammonia at ambient conditions has been a longstanding challenge. This knowledge is crucial for transferring biological nitrogen fixation to crops and developing improved synthetic catalysts. Azotobacter vinelandii has emerged as the preferred model organism for studying this process over the past 30 years. This review summarizes the current understanding and places it in historical context.
CRITICAL REVIEWS IN BIOCHEMISTRY AND MOLECULAR BIOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Christian Trncik, Tanja Mueller, Philipp Franke, Oliver Einsle
Summary: This study presents the crystal structure of the ADP-bound reductase component AnfH of the iron-only nitrogenase and compares it with other iron protein homologs. The results show that all three iron proteins adopt the same conformation. Cross-reactivity assays reveal that AnfH is compatible with iron-only nitrogenase and to a lesser degree with the vanadium-containing enzyme, but not with molybdenum nitrogenase.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2022)
Article
Plant Sciences
Samuel T. Wilson, Mathieu Caffin, Angelicque E. White, David M. Karl, B. Palenik
Summary: The study investigates the effect of different gas conditions on hydrogen production by cyanobacteria, highlighting the potential of the argon-induced hydrogen production method in evaluating nitrogenase activity. Additionally, comparison of hydrogen production under air and argon gas conditions revealed the efficiency of electron usage during nitrogen fixation process.
JOURNAL OF PHYCOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Artavazd Badalyan, Zhi-Yong Yang, Lance C. Seefeldt
Summary: The molybdenum-iron protein (MoFeP) is a component of the enzyme nitrogenase and can catalyze the reduction of various small molecules. However, it has been found that increasing the driving force alone cannot achieve efficient electrochemical activation of MoFeP.
BIOELECTROCHEMISTRY
(2024)
Article
Chemistry, Physical
Fangyuan Dong, Yoo Seok Lee, Erin M. Gaffney, Willisa Liou, Shelley D. Minteer
Summary: A genetic strategy was described to engineer a cyanobacterium with transmembrane electron transfer ability, realizing bioelectrochemical nitrogen fixation without diffusible mediators. The engineered strain exhibited significantly increased NH3 production rate and higher Faradaic efficiency compared to previously reported systems.
Article
Multidisciplinary Sciences
Hannah L. Rutledge, Brian D. Cook, Hoang P. M. Nguyen, Mark A. Herzik, F. Akif Tezcan
Summary: This study reports cryo-electron microscopy structures of the nitrogenase complex prepared under enzymatic turnover conditions. The research reveals that asymmetry plays a critical role in various aspects of the nitrogenase mechanism.
Article
Biochemistry & Molecular Biology
Hong-Wei Pi, Jinn-Jy Lin, Chi-An Chen, Po-Hsiang Wang, Yin-Ru Chiang, Chieh-Chen Huang, Chiu-Chung Young, Wen-Hsiung Li
Summary: This study provides evidence supporting the bacteria-first hypothesis in the origin of nitrogen fixation. The researchers found that in the phylogenetic trees of nitrogen-fixing proteins, the earliest lineages are bacterial sequences and the archaeal sequences are nested inside bacterial sequences. Additionally, they observed that most Nif archaea carry bacterial Mo transporter proteins. Isotopic data also support the bacteria-first hypothesis.
MOLECULAR BIOLOGY AND EVOLUTION
(2022)
Article
Multidisciplinary Sciences
Yeongin Kim, Jun Min Suh, Jiho Shin, Yunpeng Liu, Hanwool Yeon, Kuan Qiao, Hyun S. Kum, Chansoo Kim, Han Eol Lee, Chanyeol Choi, Hyunseok Kim, Doyoon Lee, Jaeyong Lee, Ji-Hoon Kang, Bo-In Park, Sungsu Kang, Jihoon Kim, Sungkyu Kim, Joshua A. Perozek, Kejia Wang, Yongmo Park, Kumar Kishen, Lingping Kong, Tomas Palacios, Jungwon Park, Min-Chul Park, Hyung-Jun Kim, Yun Seog Lee, Kyusang Lee, Sang-Hoon Bae, Wei Kong, Jiyeon Han, Jeehwan Kim
Summary: Recent advances in flexible and stretchable electronics have led to the development of electronic skin (e-skin)based health monitoring platforms. Conventional wireless e-skins use rigid integrated circuit chips, while chip-less wireless e-skins use surface acoustic wave sensors made of piezoelectric materials, which offer highly sensitive, low-power, and long-term sensing capabilities for monitoring strain, ultraviolet light, and ion concentrations in sweat. These findings provide new routes for creating inexpensive and versatile wireless health monitoring devices.
Article
Environmental Sciences
Shuaitong Liu, Ying Liu, Jian Zhang
Summary: This study investigated the effects of three commonly detected antibiotics - ciprofloxacin, tetracycline, and sulfamethoxazole - on the growth, photosynthetic activity, nitrogen-fixing capacity, and proteomic expression profiles of Nostoc sp. PCC 7120. It was found that ciprofloxacin and sulfamethoxazole stimulated cyanobacterial growth and nitrogenase synthesis, while tetracycline mainly enhanced nitrogen fixation through growth stimulation. The study also revealed that the nitrogen-fixing capacity of Nostoc sp. was closely related to the total nitrogenase concentration, which was determined by cell density and nitrogenase synthesis ability.
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
(2021)
Article
Microbiology
Alex J. Rivier, Kevin S. Myers, Amanda K. Garcia, Morgan S. Sobol, Betul Kacar
Summary: This study investigates the impact of gene regulatory dynamics on engineering biological nitrogen fixation. The results show that modulating the expression of proteins involved in cellular processes adjacent to nitrogen fixation can improve compatibility between engineered strains and nitrogenase variants. These findings provide important insights for transferring nitrogenase variants to non-native hosts.
MICROBIOLOGY SPECTRUM
(2023)
Article
Microbiology
Alex J. Rivier, Kevin S. Myers, Amanda K. Garcia, Morgan S. Sobol, Betul Kacar
Summary: Biological nitrogen fixation is a crucial process that converts atmospheric nitrogen into bioavailable ammonia, but its engineering requires a comprehensive understanding of the gene regulatory dynamics and sequence-function space of nitrogenase, the central catalytic metalloenzyme. In this study, we analyzed the transcriptome of Azotobacter vinelandii engineered with a genetically inferred ancestral nitrogenase protein variant to investigate this relationship. Our results showed resilient expression of genes within the nitrogen fixation network despite nitrogenase sequence-level perturbations, while reduced expression of genes supporting trace metal and electron resource allocation to nitrogenase accompanied the sustained physiological compatibility with the ancestral nitrogenase variant. These findings provide important insights for the engineering of nitrogenase proteins and host diazotrophs to improve compatibility.
MICROBIOLOGY SPECTRUM
(2023)
Article
Biology
Trixia M. Buscagan, Jens T. Kaiser, Douglas C. Rees
Summary: This study presents crystallographic data demonstrating chalcogenide exchange at the Fe4S4 cluster of nitrogenase Fe protein under certain conditions, revealing the unique properties of Fe protein in nitrogenase reactions.
Article
Biology
Shreya Srivastava, Hailiang Dong, Oliver Baars, Yizhi Sheng
Summary: Life on Earth depends on N-2-fixing microbes to convert atmospheric N-2 gas into ammonia. This study shows that mineral-associated trace metals, such as Mo, V, and Fe, can serve as cofactors for nitrogenases and support N-2 fixation when soluble trace metals are lacking. The results suggest a partial solution to the paradox of N-2 fixation.