THB1 is one of several group 1 truncated hemoglobins (TrHb1s) encoded in the genome of the unicellular green alga Chlamydomonas reinhardtii. THB1 expression is under the control of NIT2, the master regulator of nitrate assimilation, which also controls the expression of the only nitrate reductase in the cell, NIT1. In vitro and physiological evidence suggests that THB1 converts the nitric oxide generated by NIT1 into nitrate. To aid in the elucidation of the function and mechanism of THB1, the structure of the protein was solved in the ferric state. THB1 resembles other TrHb1s, but also exhibits distinct features associated with the coordination of the heme iron by a histidine (proximal) and a lysine (distal). The new structure illustrates the versatility of the TrHb1 fold, suggests factors that stabilize the axial ligation of a lysine, and highlights the difficulty of predicting the identity of the distal ligand, if any, in this group of proteins.
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http://dx.doi.org/10.1107/S2053230X15006949 | DOI Listing |
J Photochem Photobiol B
December 2024
Department of Biology, University of New Brunswick, Fredericton E3B5A3, NB, Canada. Electronic address:
Under ideal conditions, Chlamydomonas reinhardtii can photoacclimate to excess light through various short- and long-term mechanisms. However, how microalgae handle excess light stress once they exit exponential growth, and especially in stationary phase, is less understood. Our study explored C.
View Article and Find Full Text PDFMicrobiologyopen
December 2024
Department of Geological Sciences and Engineering, Queen's University, Kingston, Ontario, Canada.
Diclofenac (DCF), a commonly used anti-inflammatory medication, presents environmental concerns due to its presence in water bodies, resistance to conventional wastewater treatment methods, and detection at increasing concentrations (ng/L to µg/L) that highlight DCF as a global emerging pollutant. While microalgae have been effective in degrading DCF in wastewater, immobilization into a matrix offers a promising approach to enhance treatment retention and efficiency. This study aimed to evaluate the efficacy of DCF removal using immobilized freshwater microalgae.
View Article and Find Full Text PDFMicrob Biotechnol
December 2024
State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China.
Chlamydomonas reinhardtii, a model green alga for expressing foreign proteins, faces challenges in multigene expression and enhancing protein expression level in the chloroplast. To address these challenges, we compared heterologous promoters, terminators and intercistronic expression elements (IEEs). We transformed Chlamydomonas chloroplast with a biolistic approach to introduce vectors containing the NanoLuc expression unit regulated by Chlamydomonas or tobacco promoters and terminators.
View Article and Find Full Text PDFPlant Sci
December 2024
Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Suipacha 570, Rosario, Santa Fe S2002LRK, Argentina; Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe S2002LRK, Argentina. Electronic address:
Chlamydomonas reinhardtii is a green alga that has been widely used as a model organism for studying various cellular processes, including starch metabolism. In this alga, starch undergoes continuous phosphorylation during its synthesis and degradation. We recently identified and characterized ChlreSEX4 (starch excess 4), a glucan phosphatase from C.
View Article and Find Full Text PDFJ Trace Elem Med Biol
December 2024
Department of Chemistry, University of Crete, Voutes Campus, Heraklion 70013, Greece; Environmental Chemical Processes Laboratory, University of Crete, Voutes Campus, Heraklion 70013, Greece. Electronic address:
As the concern for Ni contamination in the aquatic environment escalates, efforts for microalgal use in environmental monitoring and bioremediation are increasing. This study aims to evaluate the potential of Chlorella sorokiniana and Chlamydomonas reinhardtii for Ni bioremediation by investigating their physiological stress responses in Ni-contaminated environments. The analysis focuses on how Ni(II) uptake affects cell growth, nutrient metal homeostasis, and lipid unsaturation levels, as these parameters are critical indicators of metabolic stability and resilience essential for effective bioremediation.
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