To contribute to the defeat of tuberculosis, we focus on understanding three families of small protein complexes, which are dramatically expanded within pathogenic Mycobacterial species and are believed to be among the most critical for bacterial survival and pathogenesis. We propose X-ray structural studies of complexes because these reveal how protein machines work, and how they may be disrupted. Our targets are PE/PPE complexes, associated with the cell wall and the host immune response;Esx complexes, associated with type VII secretion systems;and toxin-antitoxin complexes of which Mtb contains 88 pairs. We have developed and tested innovative methods: a computational method (PROLINKS) for predicting which pairs of proteins participate in a complex;a robust experimental method for validating predicted complexes for crystallographic studies;and new methods for optimizing crystallization (SER server). These methods allow us to determine structures of protein complexes, rather than individual molecules. We have achieved proof of principle structures for all three of our targets , and have clones and expression systems ready to rapidly expand knowledge of these potentially vulnerable Mtb complexes. In addition, we propose structural studies of the potentially vulnerable polyketide synthase system, specifically Pks13, for which we will seek structures of enzyme-substrate complexes. Through collaborative work with the Genetics and Chemical Core, the TAMU project, and our collaborators. Dr. Robert Modlin of UCLA and Dr. William Jacobs of Einstein, we will seek functional information on the complexes that we prepare. We will continue to collaborate with the Structure Determination Core on the development of methods, and will call on their facility when our structural problems exceed local capacity.

Public Health Relevance

We combat tuberculosis by revealing the structures and inferring functions of bacterially encoded molecular machines (protein complexes), thought to be among the most vulnerable components of processes essential for bacterial viability and pathogenicity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Program Projects (P01)
Project #
1P01AI095208-01A1
Application #
8353057
Study Section
Special Emphasis Panel (ZAI1-JKB-M (M1))
Project Start
Project End
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
1
Fiscal Year
2012
Total Cost
$262,483
Indirect Cost
$36,655
Name
Texas A&M University
Department
Type
DUNS #
078592789
City
College Station
State
TX
Country
United States
Zip Code
77845
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Reddy, Manchi C M; Breda, Ardala; Bruning, John B et al. (2014) Structure, activity, and inhibition of the Carboxyltransferase ?-subunit of acetyl coenzyme A carboxylase (AccD6) from Mycobacterium tuberculosis. Antimicrob Agents Chemother 58:6122-32
Baer, Christina E; Iavarone, Anthony T; Alber, Tom et al. (2014) Biochemical and spatial coincidence in the provisional Ser/Thr protein kinase interaction network of Mycobacterium tuberculosis. J Biol Chem 289:20422-33
Layre, Emilie; Lee, Ho Jun; Young, David C et al. (2014) Molecular profiling of Mycobacterium tuberculosis identifies tuberculosinyl nucleoside products of the virulence-associated enzyme Rv3378c. Proc Natl Acad Sci U S A 111:2978-83
Chim, Nicholas; Johnson, Parker M; Goulding, Celia W (2014) Insights into redox sensing metalloproteins in Mycobacterium tuberculosis. J Inorg Biochem 133:118-26
Mavrici, Daniela; Prigozhin, Daniil M; Alber, Tom (2014) Mycobacterium tuberculosis RpfE crystal structure reveals a positively charged catalytic cleft. Protein Sci 23:481-7
Mavrici, Daniela; Marakalala, Mohlopheni J; Holton, James M et al. (2014) Mycobacterium tuberculosis FtsX extracellular domain activates the peptidoglycan hydrolase, RipC. Proc Natl Acad Sci U S A 111:8037-42
Gokulan, Kuppan; O'Leary, Sean E; Russell, William K et al. (2013) Crystal structure of Mycobacterium tuberculosis polyketide synthase 11 (PKS11) reveals intermediates in the synthesis of methyl-branched alkylpyrones. J Biol Chem 288:16484-94
DeJesus, Michael A; Sacchettini, James C; Ioerger, Thomas R (2013) Reannotation of translational start sites in the genome of Mycobacterium tuberculosis. Tuberculosis (Edinb) 93:18-25
Katibah, George E; Lee, Ho Jun; Huizar, John P et al. (2013) tRNA binding, structure, and localization of the human interferon-induced protein IFIT5. Mol Cell 49:743-50

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