The bacterial glmS ribozyme is mechanistically unique among both riboswitches and RNA catalysts. Its self-cleavage activity is the basis of riboswitch regulation of glucosamine-6-phosphate (GlcN6P) production, and catalysis requires GlcN6P as a coenzyme. Previous work has shown that the coenzyme amine of GlcN6P is essential for glmS ribozyme self-cleavage, as is its protonation state. Metal ions are also essential within the glmS ribozyme core for both structure and function of the ribozyme. Although metal ions do not directly promote catalysis, we show that metal ion identity and the varying physicochemical properties of metal ions have an impact on the rate of glmS ribozyme self-cleavage. Specifically, these studies demonstrate that metal ion identity influences the overall apparent pK(a) of ribozyme self-cleavage, and metal ion binding largely reflects phosphate oxygen affinity. Results suggest that metal ions take alternative roles in supporting the mechanism of catalysis.
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http://dx.doi.org/10.1002/cbic.201000544 | DOI Listing |
Nucleic Acids Res
November 2024
T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA.
Like other functional RNAs, ribozymes encode a conserved catalytic center supported by peripheral domains that vary among ribozyme sub-families. To understand how core-periphery interactions contribute to ribozyme fitness, we compared the cleavage kinetics of all single base substitutions at 152 sites across the Bacillus subtilis glmS ribozyme by high-throughput sequencing (k-seq). The in vitro activity map mirrored phylogenetic sequence conservation in glmS ribozymes, indicating that biological fitness reports all biochemically important positions.
View Article and Find Full Text PDFMitochondrion
November 2024
International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067, India. Electronic address:
The functional mitochondrion is vital for the propagation of the malaria parasite in the human host. Members of the SPFH protein family, Prohibitins (PHBs), are known to play crucial roles in maintaining mitochondrial homeostasis and cellular functions. Here, we have functionally characterized the homologue of the Plasmodium falciparumProhibitin-2 (PfPhb2) protein.
View Article and Find Full Text PDFiScience
June 2024
Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.
Malaria parasite invasion to host erythrocytes is mediated by multiple interactions between merozoite ligands and erythrocyte receptors that contribute toward the development of disease pathology. Here, we report a novel antigen prohibitin "PHB2" and identify its cognate partner "Hsp70A1A" in host erythrocyte that plays a crucial role in mediating host-parasite interaction during merozoite invasion. Using small interfering RNA (siRNA)- and glucosamine-6-phosphate riboswitch (glmS) ribozyme-mediated approach, we show that loss of Hsp70A1A in red blood cells (RBCs) or PHB2 in infected red blood cells (iRBCs), respectively, inhibit PHB2-Hsp70A1A interaction leading to invasion inhibition.
View Article and Find Full Text PDFPeerJ
January 2024
National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, Thailand.
Background: possesses a cobalamin-dependent methionine synthase (MS). MS is putatively encoded by the PF3D7_1233700 gene, which is orthologous and syntenic in . However, its vulnerability as an antimalarial target has not been assessed.
View Article and Find Full Text PDFTalanta Open
December 2023
Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, 64108, USA.
Resolving isomeric analytes is challenging given their physical similarity - making chromatographic resolution difficult, and their identical masses - making simple mass resolution impossible. MS/MS data provides a means to resolve isomeric analytes if their MS/MS intensity profiles are sufficiently different. Glucosamine-6-phosphate (GlcN-6P) and glucosamine-1-phosphate (GlcN-1P) are early bacterial cell wall intermediates.
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