5DTP

Crystal structure of M. tuberculosis EchA6 (apo, trigonal crystal form)

Summary for 5DTP

• Entry DOI: 10.2210/pdb5dtp/pdb
• Descriptor: Probable enoyl-CoA hydratase echA6 (2 entities in total)
• Functional Keywords: enoyl-coa hydratase-like, lyase, lipid binding protein
• Biological source: Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
• Total number of polymer chains: 3
• Total formula weight: 84489.35

Authors

Cox, J.A.G.,Besra, G.S.,Futterer, K. (deposition date: 2015-09-18, release date: 2016-01-20, Last modification date: 2024-01-10)

Primary citation

Cox, J.A.,Abrahams, K.A.,Alemparte, C.,Ghidelli-Disse, S.,Rullas, J.,Angulo-Barturen, I.,Singh, A.,Gurcha, S.S.,Nataraj, V.,Bethell, S.,Remuinan, M.J.,Encinas, L.,Jervis, P.J.,Cammack, N.C.,Bhatt, A.,Kruse, U.,Bantscheff, M.,Futterer, K.,Barros, D.,Ballell, L.,Drewes, G.,Besra, G.S.
THPP target assignment reveals EchA6 as an essential fatty acid shuttle in mycobacteria.
Nat Microbiol, 1:15006-15006, 2016

PubMed Abstract: Phenotypic screens for bactericidal compounds against drug-resistant tuberculosis are beginning to yield novel inhibitors. However, reliable target identification remains challenging. Here, we show that tetrahydropyrazo[1,5-a]pyrimidine-3-carboxamide (THPP) selectively pulls down EchA6 in a stereospecific manner, instead of the previously assigned target Mycobacterium tuberculosis MmpL3. While homologous to mammalian enoyl-coenzyme A (CoA) hydratases, EchA6 is non-catalytic yet essential and binds long-chain acyl-CoAs. THPP inhibitors compete with CoA-binding, suppress mycolic acid synthesis, and are bactericidal in a mouse model of chronic tuberculosis infection. A point mutation, W133A, abrogated THPP-binding and increased both the in vitro minimum inhibitory concentration and the in vivo effective dose 99 in mice. Surprisingly, EchA6 interacts with selected enzymes of fatty acid synthase II (FAS-II) in bacterial two-hybrid assays, suggesting essentiality may be linked to feeding long-chain fatty acids to FAS-II. Finally, our data show that spontaneous resistance-conferring mutations can potentially obscure the actual target or alternative targets of small molecule inhibitors.

PubMed: 27571973
DOI: 10.1038/nmicrobiol.2015.6

Experimental method

X-RAY DIFFRACTION (1.91 Å)