Three protein factors ensure rapid and accurate initiation of translation in bacteria. Translation initiation factor IF2 is a ribosome-dependent GTPase, which is important for correct positioning of initiator tRNA on the 30S subunit as well as ribosomal subunit joining. The solution structure of the free C-terminal part of IF2 (IF2C, comprising domains IV to VI-2) was previously determined by small-angle X-ray scattering (SAXS) [Rasmussen, L. C., et al. (2008) Biochemistry 47, 5590-5598]. In this study, adding GDP or nonhydrolyzable GTP analogue GDPNP to the protein in solution caused structural changes in the protein, in agreement with recent data determined via isothermal titration calorimetry [Hauryliuk, V., et al. (2009) J. Mol. Biol. 394, 621-626]. The p(r) function indicated an elongated conformation supported by radii of gyration of 40.1 and 44.9 Å and maximum dimensions of ~125 and ~150 Å for IF2C with GDPNP and GDP, respectively. The SAXS data were used to model the structure of IF2C bound to either GDPNP or GDP. The structural transitions of IF2C upon GDPNP binding and following nucleotide hydrolysis support the concept of cofactor-dependent conformational switching rather than the classical model for GTPase activity.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/bi200938q | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Identification of hub genes and potential networks by centrality network analysis of PCR amplified Fusarium oxysporum f. sp. lycopersici EF1α gene.
BMC Microbiol
September 2024
Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Background: Fusarium wilt is a devastating soil-borne fungal disease of tomato across the world. Conventional method of disease prevention including usage of common pesticides and methods like soil solarisation are usually ineffective in the treatment of this disease. Therefore, there is an urgent need to identify virulence related genes in the pathogen which can be targeted for fungicide development.
View Article and Find Full Text PDFE. coli elongation factor Tu bound to a GTP analogue displays an open conformation equivalent to the GDP-bound form.
Nucleic Acids Res
September 2018
Department of Molecular Biology & Genetics, University of Aarhus, Gustav Wieds Vej 10 C, DK-8000 Aarhus C, Denmark.
According to the traditional view, GTPases act as molecular switches, which cycle between distinct 'on' and 'off' conformations bound to GTP and GDP, respectively. Translation elongation factor EF-Tu is a GTPase essential for prokaryotic protein synthesis. In its GTP-bound form, EF-Tu delivers aminoacylated tRNAs to the ribosome as a ternary complex.
View Article and Find Full Text PDFImpact of G12 Mutations on the Structure of K-Ras Probed by Ultraviolet Photodissociation Mass Spectrometry.
J Am Chem Soc
October 2016
Department of Chemistry, ‡Graduate Program in Biochemistry, and §Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States.
Single-residue mutations at Gly12 (G12X) in the GTP-ase protein K-Ras can lead to activation of different downstream signaling pathways, depending on the identity of the mutation, through a poorly defined mechanism. Herein, native mass spectrometry combined with top-down ultraviolet photodissociation (UVPD) was employed to investigate the structural changes occurring from G12X mutations of K-Ras. Complexes between K-Ras or the G12X mutants and guanosine 5'-diphosphate (GDP) or GDPnP (a stable GTP analogue) were transferred to the gas phase by nano-electrospray ionization and characterized using UVPD.
View Article and Find Full Text PDFStructural outline of the detailed mechanism for elongation factor Ts-mediated guanine nucleotide exchange on elongation factor Tu.
J Struct Biol
July 2015
Aarhus University, Department of Molecular Biology and Genetics, Center for Structural Biology, DK-8000 Aarhus C, Denmark.
Translation elongation factor EF-Tu belongs to the superfamily of guanine-nucleotide binding proteins, which play key cellular roles as regulatory switches. All G-proteins require activation via exchange of GDP for GTP to carry out their respective tasks. Often, guanine-nucleotide exchange factors are essential to this process.
View Article and Find Full Text PDFTranslation termination is promoted by class 1 and class 2 release factors in all domains of life. While the role of the bacterial class 1 factors, RF1 and RF2, in translation termination is well understood, the precise contribution of the bacterial class 2 release factor, RF3, to this process remains less clear. Here, we use a combination of binding assays and pre-steady state kinetics to provide a kinetic and thermodynamic framework for understanding the role of the translational GTPase RF3 in bacterial translation termination.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!