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Title: mRNA bound to the 30S subunit is a HigB toxin substrate

Authors:
; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1274774
Resource Type:
Journal Article
Resource Relation:
Journal Name: RNA; Journal Volume: 22; Journal Issue: 8
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Schureck, Marc A., Maehigashi, Tatsuya, Miles, Stacey J., Marquez, Jhomar, and Dunham, Christine M. mRNA bound to the 30S subunit is a HigB toxin substrate. United States: N. p., 2016. Web. doi:10.1261/rna.056218.116.
Schureck, Marc A., Maehigashi, Tatsuya, Miles, Stacey J., Marquez, Jhomar, & Dunham, Christine M. mRNA bound to the 30S subunit is a HigB toxin substrate. United States. doi:10.1261/rna.056218.116.
Schureck, Marc A., Maehigashi, Tatsuya, Miles, Stacey J., Marquez, Jhomar, and Dunham, Christine M. 2016. "mRNA bound to the 30S subunit is a HigB toxin substrate". United States. doi:10.1261/rna.056218.116.
@article{osti_1274774,
title = {mRNA bound to the 30S subunit is a HigB toxin substrate},
author = {Schureck, Marc A. and Maehigashi, Tatsuya and Miles, Stacey J. and Marquez, Jhomar and Dunham, Christine M.},
abstractNote = {},
doi = {10.1261/rna.056218.116},
journal = {RNA},
number = 8,
volume = 22,
place = {United States},
year = 2016,
month = 6
}
  • ADP-ribosylation induced by cholera toxin and pertussis toxin was studied in particulate and cytosolic fractions of human platelets. Platelets were disrupted by a cycle of freezing and thawing in the presence of a hyposmotic buffer containing protease inhibitors. In both fractions, the A subunit of cholera toxin ADP-ribosylates two proteins with molecular masses of 42 and 44 kDa, whereas pertussis toxin ADP-ribosylates a 41-kDa polypeptide. Two antisera against the {alpha} subunit of the stimulatory guanine nucleotide-binding regulatory protein recognize only the 42-kDa polypeptide. Cholera toxin-induced ADP-ribosylation of the 42- and 44-kDa proteins is reduced by pretreatment of platelets with iloprost,more » a prostacyclin analog. The 44-kDa protein, which is substrate of cholera toxin, could be extracted completely from the membrane and recovered in the cytosolic fraction when the cells were disrupted by Dounce homogenization and the pellet was extensively washed. A 44-kDa protein can also be labeled with 8-azidoguanosine 5{prime}-({alpha}-{sup 32}P)triphosphate in the cytosol and membranes. These finding indicate that cholera and pertussis toxins produced covalent modifications of proteins present in particulate and cytosolic platelet fractions. Moreover, the 44-kDa protein might be an {alpha} subunit of a guanine nucleotide-binding regulatory protein that is not recognized by available antisera.« less
  • Bacteria contain multiple type II toxins that selectively degrade mRNAs bound to the ribosome to regulate translation and growth and facilitate survival during the stringent response. Ribosome-dependent toxins recognize a variety of three-nucleotide codons within the aminoacyl (A) site, but how these endonucleases achieve substrate specificity remains poorly understood. In this paper, we identify the critical features for how the host inhibition of growth B (HigB) toxin recognizes each of the three A-site nucleotides for cleavage. X-ray crystal structures of HigB bound to two different codons on the ribosome illustrate how HigB uses a microbial RNase-like nucleotide recognition loop tomore » recognize either cytosine or adenosine at the second A-site position. Strikingly, a single HigB residue and 16S rRNA residue C1054 form an adenosine-specific pocket at the third A-site nucleotide, in contrast to how tRNAs decode mRNA. Finally, our results demonstrate that the most important determinant for mRNA cleavage by ribosome-dependent toxins is interaction with the third A-site nucleotide.« less