The adsorption of proteins and its buffer solution on mica surfaces was investigated by atomic force microscopy (AFM). Different salt concentration of the Herbaspirillum seropedicae GlnB protein (GlnB-Hs) solution deposited on mica was investigated. This protein is a globular, soluble homotrimer (36kDa), member of PII-like proteins family involved in signal transducing in prokaryote. Supramolecular structures were formed when this protein was deposited onto bare mica surface. The topographic AFM images of the GlnB-Hs films showed that at high salt concentration the supramolecular structures are spherical-like, instead of the typical doughnut-like shape for low salt concentration. AFM images of NaCl and Tris from the buffer solution showed structures with the same pattern as those observed for high salt protein solution, misleading the image interpretation. XPS experiments showed that GlnB protein film covers the mica surface without chemical reaction.
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http://dx.doi.org/10.1016/j.colsurfb.2009.05.034 | DOI Listing |
Plant Physiol Biochem
January 2025
Laboratory of Microbial Genetics, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address:
Nitric oxide synthases (NOSs) are heme-based monooxygenases that catalyze the NADPH-dependent oxidation of L-arginine to produce NO and L-citrulline. Over the past five years, the identification and characterization of NOS homologs in cyanobacteria have significantly advanced our understanding of these enzymes. However, the precise mechanisms through which NOS-derived NO influences nitrogen metabolism remain incompletely elucidated.
View Article and Find Full Text PDFXi Bao Yu Fen Zi Mian Yi Xue Za Zhi
November 2024
Department of Microbiology and Immunology, School of Basic Medical Sciences, Dali University, Dali 671000, China. *Corresponding author, E-mail:
Objective To predict and analyze the structure and function of the protein encoding the Mycobacterium tuberculosis (Mtb) Rv2387 gene by bioinformatics methods. Methods Basic information about the Rv2387 gene and the protein it encodes was obtained from the National Center for Biological Information (NCBI) database. Physicochemical properties and the hydrophilicity/hydrophobicity of proteins were predicted using ProtParam and ProtScale tools; TMHMM-2.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Setor Litoral, UFPR Matinhos, Paraná, Brazil; Programa de Pós-Graduação em Ciências - Bioquímica, UFPR Curitiba, Paraná, Brazil. Electronic address:
The PII signaling proteins are ubiquitous in prokaryotes serving as crucial metabolic hubs in different metabolic pathways because of their ability to sense and integrate signals of the cellular nitrogen, carbon, and energy levels. In this study, we used ligand fishing assays to identify the ribonucleotide monophosphatase UmpH enzyme as a novel target of the PII signaling protein GlnK in Escherichia coli. In vitro analyses showed that UmpH interacts specifically with the PII protein GlnK but not with its paralog protein GlnB.
View Article and Find Full Text PDFFront Microbiol
March 2024
Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
PII proteins are signal transduction proteins that belong to a widely distributed family of proteins involved in the modulation of different metabolisms in bacteria. These proteins are homotrimers carrying a flexible loop, named T-loop, which changes its conformation due to the recognition of diverse key metabolites, ADP, ATP, and 2-oxoglutarate. PII proteins interact with different partners to primarily regulate a set of nitrogen pathways.
View Article and Find Full Text PDFNucleic Acids Res
April 2024
Laboratory Medicine, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou 510000, China.
Adjusting intracellular metabolic pathways and adopting suitable live state such as biofilms, are crucial for bacteria to survive environmental changes. Although substantial progress has been made in understanding how the histone-like nucleoid-structuring (H-NS) protein modulates the expression of the genes involved in biofilm formation, the precise modification that the H-NS protein undergoes to alter its DNA binding activity is still largely uncharacterized. This study revealed that acetylation of H-NS at Lys19 inhibits biofilm development in Shewanella oneidensis MR-1 by downregulating the expression of glutamine synthetase, a critical enzyme in glutamine synthesis.
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