5cee

Malic enzyme from Candidatus Phytoplasma AYWB in complex with NAD and Mg2+

spinqualitylabelsall models 5cee, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5cee is a 1 chain structure with sequence from Aster yellows witches'-broom phytoplasma AYWB. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.498Å Ligands: MG, NAD Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q2NK75_AYWBP Publication Abstract from PubMed Phytoplasmas are wall-less phytopathogenic bacteria that produce devastating effects in a wide variety of plants. Reductive evolution has shaped their genome, with the loss of many genes, limiting their metabolic capacities. Owing to the high concentration of C4 compounds in plants, and the presence of malic enzyme (ME) in all phytoplasma genomes so far sequenced, the oxidative decarboxylation of L-malate might represent an adaptation to generate energy. Aster yellows witches'-broom (Candidatus Phytoplasma) ME (AYWB-ME) is one of the smallest of all characterized MEs, yet retains full enzymatic activity. Here, the crystal structure of AYWB-ME is reported, revealing a unique fold that differs from those of `canonical' MEs. AYWB-ME is organized as a dimeric species formed by intertwining of the N-terminal domains of the protomers. As a consequence of such structural differences, key catalytic residues such as Tyr36 are positioned in the active site of each protomer but are provided by the other protomer of the dimer. A Tyr36Ala mutation abolishes the catalytic activity, indicating the key importance of this residue in the catalytic process but not in the dimeric assembly. Phylogenetic analyses suggest that larger MEs (large-subunit or chimeric MEs) might have evolved from this type of smaller scaffold by gaining small sequence cassettes or an entire functional domain. The Candidatus Phytoplasma AYWB-ME structure showcases a novel minimal structure design comprising a fully functional active site, making this enzyme an attractive starting point for rational genetic design. The crystal structure of the malic enzyme from Candidatus Phytoplasma reveals the minimal structural determinants for a malic enzyme.,Alvarez CE, Trajtenberg F, Larrieux N, Saigo M, Golic A, Andreo CS, Hogenhout SA, Mussi MA, Drincovich MF, Buschiazzo A Acta Crystallogr D Struct Biol. 2018 Apr 1;74(Pt 4):332-340. doi:, 10.1107/S2059798318002759. Epub 2018 Apr 6. PMID:29652260 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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