4gsq
Structural basis for the inhibition of Mycobacterium tuberculosis L,D-transpeptidase by meropenem, a drug effective against extensively drug-resistant strainsStructural basis for the inhibition of Mycobacterium tuberculosis L,D-transpeptidase by meropenem, a drug effective against extensively drug-resistant strains
Structural highlights
FunctionLDT2_MYCTO Generates 3->3 cross-links in peptidoglycan, catalyzing the cleavage of the mDap(3)-D-Ala(4) bond of a tetrapeptide donor stem and the formation of a bond between the carbonyl of mDap(3) of the donor stem and the side chain of mDap(3) of the acceptor stem. Is specific for donor substrates containing a stem tetrapeptide since it cannot use pentapeptide stems. Is essential for virulence in a mouse model of acute infection.[1] Publication Abstract from PubMedDifficulty in the treatment of tuberculosis and growing drug resistance in Mycobacterium tuberculosis (Mtb) are a global health issue. Carbapenems inactivate L,D-transpeptidases; meropenem, when administered with clavulanate, showed in vivo activity against extensively drug-resistant Mtb strains. LdtMt2 (Rv2518c), one of two functional L,D-transpeptidases in Mtb, is predominantly expressed over LdtMt1 (Rv0116c). Here, the crystal structure of N-terminally truncated LdtMt2 (residues Leu131-Ala408) is reported in both ligand-free and meropenem-bound forms. The structure of meropenem-inhibited LdtMt2 provides a detailed structural view of the interactions between a carbapenem drug and Mtb L,D-transpeptidase. The structures revealed that the catalytic L,D-transpeptidase domain of LdtMt2 is preceded by a bacterial immunogloblin-like Big_5 domain and is followed by an extended C-terminal tail that interacts with both domains. Furthermore, it is shown using mass analyses that meropenem acts as a suicide inhibitor of LdtMt2. Upon acylation of the catalytic Cys354 by meropenem, the `active-site lid' undergoes a large conformational change to partially cover the active site so that the bound meropenem is accessible to the bulk solvent via three narrow paths. This work will facilitate structure-guided discovery of L,D-transpeptidase inhibitors as novel antituberculosis drugs against drug-resistant Mtb. Structural basis for the inhibition of Mycobacterium tuberculosis L,D-transpeptidase by meropenem, a drug effective against extensively drug-resistant strains.,Kim HS, Kim J, Im HN, Yoon JY, An DR, Yoon HJ, Kim JY, Min HK, Kim SJ, Lee JY, Han BW, Suh SW Acta Crystallogr D Biol Crystallogr. 2013 Mar;69(Pt 3):420-31. doi:, 10.1107/S0907444912048998. Epub 2013 Feb 16. PMID:23519417[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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