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Developing a Physical Model of HigB Toxin and its Endonuclease Cleavage Mechanism
Author(s) -
Chabbra Alesa,
Alzamora Carolina,
Ghali Helana,
Handal Marina,
Kathiria Mahima,
Martinek Alexander,
Nguyen Jenny,
Patel Chandni,
Patel Shreja,
Pham Antoine,
Lavin Emily Schmitt
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.454.3
Subject(s) - ribosome , antitoxin , cleavage (geology) , ribosomal protein , biology , bacteria , escherichia coli , protein biosynthesis , ribosomal rna , rna , microbiology and biotechnology , toxin , genetics , gene , paleontology , fracture (geology)
The CREST (Connecting Researchers, Educators, and STudents) team at Nova Southeastern University created a physical model depicting the mechanism of endonuclease cleavage by the HigB protein as described in the literature. The proteins, toxin HigB and antitoxin HigA, are part of a type II toxin‐antitoxin system that cleaves ribosome‐bound mRNAs in bacteria. Chemical or physical stresses, such as extreme temperatures and lack of nutrients, lead to antitoxin degradation that releases HigB. Temporary inhibition of growth by HigB allows cells to more efficiently utilize current resources. Although HigB is referred to as a toxin, it is not inherently detrimental and can be beneficial to cellular survival. Bacteria that use this mechanism include Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris. As such, HigB is of clinical interest due to its contribution in prolonging bacterial infections through antibiotic tolerance (persistence). When cells are not in a stressed state, HigA binds to and inactivates HigB, allowing growth and translation to proceed. Details of HigB in complex with the ribosome as well as residues important for mRNA cleavage were found in the Protein Data Bank file, 4ZSN, and imported into Jmol, a protein visualization software. The 4ZSN file consisted of several nucleic acid and protein bundles; Bundle 1 was examined in more detail. Specific program commands were developed to manipulate the original file into a format that was later 3‐D printed to create an instructional molecular model, which was funded in part by NSF‐DUE 1725940 for the CREST Project. This model highlights the ribosomal proteins, ribosomal RNA, and HigB along with its residues that are essential for mRNA cleavage. The N and C termini of the HigB protein were also indicated. This molecular model can be used to explain how ribosome‐dependent proteins (HigB) target ribosome‐bound mRNAs in bacterial systems. Providing a 3‐D tool allows students to engage actively in understanding the complex process of endonuclease cleavage. Support or Funding Information The development of this 3‐D molecular model was funded in part by NSF‐DUE 1725940 for the CREST (Connecting Researchers, Educators, and STudents) Project. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .