RbcX is a dimeric protein found in cyanobacteria that assists in the assembly of the oligomeric RuBisCO complex. RbcX from the thermophile Thermosynechococcus elongatus (TeRbcX) contains an unusual Cys103 residue in its sequence and when expressed recombinantly the protein aggregates and cannot be crystallized. Site-directed mutagenesis of Cys103 to either Arg or Ala produced non-aggregating proteins that could be readily crystallized in several crystal forms. Synchrotron-radiation X-ray diffraction data were collected to 1.96 A resolution and formed the basis of crystal structure analysis of TeRbcX.
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http://dx.doi.org/10.1107/S174430910802678X | DOI Listing |
Biochemistry
December 2024
Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan.
Photosystem I (PSI) from utilizes chlorophyll (Chl) with a formyl group as its primary pigment, which is more red-shifted than chlorophyll (Chl) in PSI from . Using the cryo-electron microscopy structure and solving the linear Poisson-Boltzmann equation, here we report the redox potential () values in PSI. The (Chl) values at the paired chlorophyll site, [PP], are nearly identical to the corresponding (Chl) values in PSI, despite Chl having a 200 mV lower reduction power.
View Article and Find Full Text PDFInt J Biol Macromol
November 2024
Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China. Electronic address:
Here, we enzymatically produced a novel α-1,2-glucan, glucosylsucrose, that has a chemical structure significantly different from that of other glucans. This structural difference suggests its potential to modulate new physiological activities compared to known glucans. The enzyme TeGSS catalyzes the synthesis of this α-1,2-glucan from sucrose and UDP-glucose (UDPG).
View Article and Find Full Text PDFSci Rep
June 2024
Louvain Institute of Biomolecular Science and Technology, UCLouvain, Place Croix du Sud 4-5, 1348, Louvain-la-Neuve, Belgium.
Penicillin binding proteins (PBPs) are involved in biosynthesis, remodeling and recycling of peptidoglycan (PG) in bacteria. PBP-A from Thermosynechococcus elongatus belongs to a cyanobacterial family of enzymes sharing close structural and phylogenetic proximity to class A β-lactamases. With the long-term aim of converting PBP-A into a β-lactamase by directed evolution, we simulated what may happen when an organism like Escherichia coli acquires such a new PBP and observed growth defect associated with the enzyme activity.
View Article and Find Full Text PDFInt J Mol Sci
April 2024
Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
We establish a general kinetic scheme for the energy transfer and radical-pair dynamics in photosystem I (PSI) of , PCC6803, and grown under white-light conditions. With the help of simultaneous target analysis of transient-absorption data sets measured with two selective excitations, we resolved the spectral and kinetic properties of the different species present in PSI. WL-PSI can be described as a Bulk Chl in equilibrium with a higher-energy Chl one or two Red Chl and a reaction-center compartment (WL-RC).
View Article and Find Full Text PDFBiomolecules
March 2024
Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
Phycocyanobilin (PCB) is a natural blue tetrapyrrole chromophore that is found in phycocyanin and plays an essential role in photosynthesis. Due to PCB's antioxidation, anti-inflammatory and anti-cancer properties, it has been utilized in the food, pharmaceutical and cosmetic industries. Currently, the extraction of PCB from involves complex processes, which has led to increasing interest in the biosynthesis of PCB in .
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