4qvh
From Proteopedia
Crystal structure of the essential Mycobacterium tuberculosis phosphopantetheinyl transferase PptT, solved as a fusion protein with maltose binding protein
Structural highlights
FunctionMALE_ECOLI Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides.PPTT_MYCTU Transfers the 4'-phosphopantetheine moiety from coenzyme A to a Ser of acyl-carrier-protein (PubMed:9831524, PubMed:16709676, PubMed:25785780, PubMed:28203522). Involved in post-translational modification of various type-I polyketide synthases required for the formation of both mycolic acids and lipid virulence factors (PubMed:16709676). Acts on Pks13, Mas, PpsA, PpsB, PpsC and PpsD (PubMed:16709676, PubMed:28203522). Also acts on AcpM, the meromycolate extension acyl carrier protein (PubMed:25785780). In addition, is involved in the activation of the acyl carrier protein MbtL and the nonribosomal peptides synthases MbtB and MbtE, which are involved in the biosynthesis of the siderophore mycobactin (PubMed:9831524, PubMed:28203522).[1] [2] [3] [4] Required for the replication and survival of Mycobacterium during the acute and chronic phases of infection in mice.[5] Publication Abstract from PubMedPhosphopantetheinyl transferases (PPTases) are key enzymes in the assembly-line production of complex molecules such as fatty acids, polyketides and polypeptides, where they activate acyl or peptidyl carrier proteins, transferring a 4'-phosphopantetheinyl moiety from coenzyme A (CoA) to a reactive serine residue on the carrier protein. The human pathogen Mycobacterium tuberculosis encodes two PPTases, both essential and therefore attractive drug targets. We report the structure of the type-II PPTase PptT, obtained from crystals of a fusion protein with maltose binding protein. The structure, at 1.75A resolution (R=0.156, Rfree=0.191), reveals an alpha/beta fold broadly similar to other type-II PPTases, but with differences in peripheral structural elements. A bound CoA is clearly defined with its pantetheinyl arm tucked into a hydrophobic pocket. Interactions involving the CoA diphosphate, bound Mg2+ and three active site acidic side chains suggest a plausible pathway for proton transfer during catalysis. Crystal structure of the essential Mycobacterium tuberculosis phosphopantetheinyl transferase PptT, solved as a fusion protein with maltose binding protein.,Jung J, Bashiri G, Johnston JM, Brown AS, Ackerley DF, Baker EN J Struct Biol. 2014 Oct 18;188(3):274-278. doi: 10.1016/j.jsb.2014.10.004. PMID:25450595[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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