7X7Z
The crystal structure of 2+2/4+2 cyclase PloI4
Summary for 7X7Z
Entry DOI | 10.2210/pdb7x7z/pdb |
Descriptor | PloI4 (2 entities in total) |
Functional Keywords | ploi4, 2+2/4+2 cyclase, lyase |
Biological source | Micromonospora sp. |
Total number of polymer chains | 4 |
Total formula weight | 61992.64 |
Authors | |
Primary citation | Wang, H.,Zou, Y.,Li, M.,Tang, Z.,Wang, J.,Tian, Z.,Strassner, N.,Yang, Q.,Zheng, Q.,Guo, Y.,Liu, W.,Pan, L.,Houk, K.N. A cyclase that catalyses competing 2 + 2 and 4 + 2 cycloadditions. Nat.Chem., 15:177-184, 2023 Cited by PubMed Abstract: Cycloaddition reactions are among the most widely used reactions in chemical synthesis. Nature achieves these cyclization reactions with a variety of enzymes, including Diels-Alderases that catalyse concerted 4 + 2 cycloadditions, but biosynthetic enzymes with 2 + 2 cyclase activity have yet to be discovered. Here we report that PloI4, a β-barrel-fold protein homologous to the exo-selective 4 + 2 cyclase that functions in the biosynthesis of pyrroindomycins, catalyses competitive 2 + 2 and 4 + 2 cycloaddition reactions. PloI4 is believed to catalyse an endo-4 + 2 cycloaddition in the biosynthesis of pyrrolosporin A; however, when the substrate precursor of pyrroindomycins was treated with PloI4, an exo-2 + 2 adduct was produced in addition to the exo- and endo-4 + 2 adducts. Biochemical characterizations, computational analyses, (co)crystal structures and mutagenesis outcomes have allowed the catalytic versatility of PloI4 to be rationalized. Mechanistic studies involved the directed engineering of PloI4 to variants that produced the exo-4 + 2, endo-4 + 2 or exo-2 + 2 product preferentially. This work illustrates an enzymatic thermal 2 + 2 cycloaddition and provides evidence of a process through which an enzyme evolves along with its substrate for specialization and activity improvement. PubMed: 36690833DOI: 10.1038/s41557-022-01104-x PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.903 Å) |
Structure validation
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