6ajg
From Proteopedia
Crystal structure of mycolic acid transporter MmpL3 from Mycobacterium smegmatis complexed with SQ109
Structural highlights
FunctionD9IEF7_BPT4 MMPL3_MYCS2 Transports trehalose monomycolate (TMM) to the cell wall (PubMed:31239378, PubMed:22520756, PubMed:28698380). Flips TMM across the inner membrane. Membrane potential is not required for this function (PubMed:28698380). Transports probably phosphatidylethanolamine (PE) as well. Binds specifically both TMM and PE, but not trehalose dimycolate (TDM). Binds also diacylglycerol (DAG) and other phospholipids, including phosphatidylglycerol (PG), phosphatidylinositol (PI), and cardiolipin (CDL) (PubMed:31113875). Contributes to membrane potential, cell wall composition, antibiotic susceptibility and fitness (PubMed:28703701).[1] [2] [3] [4] [5] Publication Abstract from PubMedDespite intensive efforts to discover highly effective treatments to eradicate tuberculosis (TB), it remains as a major threat to global human health. For this reason, new TB drugs directed toward new targets are highly coveted. MmpLs (Mycobacterial membrane proteins Large), which play crucial roles in transporting lipids, polymers and immunomodulators and which also extrude therapeutic drugs, are among the most important therapeutic drug targets to emerge in recent times. Here, crystal structures of mycobacterial MmpL3 alone and in complex with four TB drug candidates, including SQ109 (in Phase 2b-3 clinical trials), are reported. MmpL3 consists of a periplasmic pore domain and a twelve-helix transmembrane domain. Two Asp-Tyr pairs centrally located in this domain appear to be key facilitators of proton-translocation. SQ109, AU1235, ICA38, and rimonabant bind inside the transmembrane region and disrupt these Asp-Tyr pairs. This structural data will greatly advance the development of MmpL3 inhibitors as new TB drugs. Crystal Structures of Membrane Transporter MmpL3, an Anti-TB Drug Target.,Zhang B, Li J, Yang X, Wu L, Zhang J, Yang Y, Zhao Y, Zhang L, Yang X, Yang X, Cheng X, Liu Z, Jiang B, Jiang H, Guddat LW, Yang H, Rao Z Cell. 2019 Jan 24;176(3):636-648.e13. doi: 10.1016/j.cell.2019.01.003. PMID:30682372[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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