Analysis of the Open and Closed Conformations of the GTP-binding Protein YsxC from Bacillus subtilis

2004 ◽  
Vol 339 (2) ◽  
pp. 265-278 ◽  
Author(s):  
Sergey N. Ruzheinikov ◽  
Sanjan K. Das ◽  
Svetlana E. Sedelnikova ◽  
Patrick J. Baker ◽  
Peter J. Artymiuk ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Binding Protein ◽  
Gtp Binding Protein ◽  
Gtp Binding

scholarly journals The Growth-Promoting and Stress Response Activities of the Bacillus subtilis GTP Binding Protein Obg Are Separable by Mutation

2008 ◽  
Vol 190 (20) ◽  
pp. 6625-6635 ◽  
Author(s):  
Shrin Kuo ◽  
Borries Demeler ◽  
W. G. Haldenwang
Keyword(s):  
Transcription Factor ◽  
Bacillus Subtilis ◽  
Amino Acid ◽  
Binding Protein ◽  
Normal Growth ◽  
Gtp Binding Protein ◽  
Missense Change ◽  
Gtp Binding ◽  
Growth Promoting ◽  
Carboxy Terminal

ABSTRACT Bacillus subtilis Obg is a ribosome-associating GTP binding protein that is needed for growth, sporulation, and induction of the bacterium's general stress regulon (GSR). It is unclear whether the roles of Obg in sporulation and stress responsiveness are direct or a secondary effect of its growth-promoting functions. The present work addresses this question by an analysis of two obg alleles whose phenotypes argue for direct roles for Obg in each process. The first allele [obg(G92D)] encodes a missense change in the protein's highly conserved “obg fold” region. This mutation impairs cell growth and the ability of Obg to associate with ribosomes but fails to block sporulation or the induction of the GSR. The second obg mutation [obg(Δ22)] replaces the 22-amino-acid carboxy-terminal sequence of Obg with an alternative 26-amino-acid sequence. This Obg variant cofractionates with ribosomes and allows normal growth but blocks sporulation and impairs the induction of the GSR. Additional experiments revealed that the block on sporulation occurs early, preventing the activation of the essential sporulation transcription factor Spo0A, while inhibition of the GSR appears to involve a failure of the protein cascade that normally activates the GSR to effectively catalyze the reactions needed to activate the GSR transcription factor (σB).

scholarly journals The GTP-binding protein YqeH participates in biogenesis of the 30S ribosome subunit in Bacillus subtilis

2007 ◽  
Vol 82 (4) ◽  
pp. 281-289 ◽  
Author(s):  
Pek Chin Loh ◽  
Takuya Morimoto ◽  
Yoshitaka Matsuo ◽  
Taku Oshima ◽  
Naotake Ogasawara
Keyword(s):  
Bacillus Subtilis ◽  
Binding Protein ◽  
Gtp Binding Protein ◽  
Gtp Binding

flhF, a Bacillus subtilis flagellar gene that encodes a putative GTP-binding protein

1992 ◽  
Vol 6 (18) ◽  
pp. 2705-2713 ◽  
Author(s):  
Phillip B. Carpenter ◽  
David W. Hanlon ◽  
George W. Ordal
Keyword(s):  
Bacillus Subtilis ◽  
Binding Protein ◽  
Flagellar Gene ◽  
Gtp Binding Protein ◽  
Gtp Binding

scholarly journals YsxC, a Putative GTP-Binding Protein Essential for Growth of Bacillus subtilis 168

2000 ◽  
Vol 182 (23) ◽  
pp. 6819-6823 ◽  
Author(s):  
Zoltán Prágai ◽  
Colin R. Harwood
Keyword(s):  
Bacillus Subtilis ◽  
Binding Proteins ◽  
Essential Gene ◽  
Binding Protein ◽  
Inducible Promoter ◽  
Gtp Binding Protein ◽  
Diverse Range ◽  
Gtp Binding Proteins ◽  
Bacillus Subtilis 168 ◽  
Gtp Binding

ABSTRACT YsxC is a member of a family of GTP-binding proteins carried by a diverse range of organisms from bacteria to yeasts, plants, and humans. To resolve the issue of whether ysxC of Bacillus subtilis is essential for growth, we attempted to construct mutants in which ysxC was either inactivated or placed under the control of an inducible promoter. Viable mutants were obtained only in the latter case, and these were inducer dependent, demonstrating unambiguously that ysxC is an essential gene.

scholarly journals The Bacillus subtilis GTP Binding Protein Obg and Regulators of the ςB Stress Response Transcription Factor Cofractionate with Ribosomes

2000 ◽  
Vol 182 (10) ◽  
pp. 2771-2777 ◽  
Author(s):  
Janelle M. Scott ◽  
Jingliang Ju ◽  
Theresa Mitchell ◽  
W. G. Haldenwang
Keyword(s):  
Transcription Factor ◽  
Bacillus Subtilis ◽  
Fluorescent Protein ◽  
Binding Protein ◽  
Fluorescent Microscopy ◽  
Gel Filtration ◽  
Gtp Binding Protein ◽  
Ribosomal Subunits ◽  
Gtp Binding ◽  
Stress Activation

ABSTRACT Obg, an essential GTP binding protein of Bacillus subtilis, is necessary for stress activation of the ςB transcription factor. We investigated Obg's cellular associations by differential centrifugation of crude B. subtilis extracts, using an anti-Obg antibody as a probe to monitor Obg during the fractionation, and by fluorescent microscopy of a B. subtilis strain in which Obg was fused to green fluorescent protein. The results indicated that Obg is part of a large cytoplasmic complex. In subsequent analyses, Obg coeluted with ribosomal subunits during gel filtration of B. subtilislysates on Sephacryl S-400 and specifically bound to ribosomal protein L13 in an affinity blot assay. Probing the gel filtration fractions with antibodies specific for ςB and its coexpressed regulators (Rsb proteins) revealed coincident elution of the upstream components of the ςB stress activation pathway (RsbR, -S, and -T) with Obg and the ribosomal subunits. The data implicate ribosome function as a possible mediator of the activity of Obg and the stress induction of ςB.

Small GTP-binding Protein RalA Associates with Weibel-Palade Bodies in Endothelial Cells

1999 ◽  
Vol 82 (09) ◽  
pp. 1177-1181 ◽  
Author(s):  
Hubert de Leeuw ◽  
Pauline Wijers-Koster ◽  
Jan van Mourik ◽  
Jan Voorberg
Keyword(s):  
Endothelial Cells ◽  
Binding Proteins ◽  
Binding Protein ◽  
Control Release ◽  
Small Gtpase ◽  
Gtp Binding Protein ◽  
Two Dimensional Gel Electrophoresis ◽  
Gtp Binding Proteins ◽  
Dense Granules ◽  
Gtp Binding

SummaryIn endothelial cells von Willebrand factor (vWF) and P-selectin are stored in dense granules, so-called Weibel-Palade bodies. Upon stimulation of endothelial cells with a variety of agents including thrombin, these organelles fuse with the plasma membrane and release their content. Small GTP-binding proteins have been shown to control release from intracellular storage pools in a number of cells. In this study we have investigated whether small GTP-binding proteins are associated with Weibel-Palade bodies. We isolated Weibel-Palade bodies by centrifugation on two consecutive density gradients of Percoll. The dense fraction in which these subcellular organelles were highly enriched, was analysed by SDS-PAGE followed by GTP overlay. A distinct band with an apparent molecular weight of 28,000 was observed. Two-dimensional gel electrophoresis followed by GTP overlay revealed the presence of a single small GTP-binding protein with an isoelectric point of 7.1. A monoclonal antibody directed against RalA showed reactivity with the small GTP-binding protein present in subcellular fractions that contain Weibel-Palade bodies. The small GTPase RalA was previously identified on dense granules of platelets and on synaptic vesicles in nerve terminals. Our observations suggest that RalA serves a role in regulated exocytosis of Weibel-Palade bodies in endothelial cells.

Sign in / Sign up

Export Citation Format

Share Document