6k3c
Crystal structure of class I PHA synthase (PhaC) mutant from Chromobacterium sp. USM2 bound to Coenzyme A.Crystal structure of class I PHA synthase (PhaC) mutant from Chromobacterium sp. USM2 bound to Coenzyme A.
Structural highlights
FunctionPublication Abstract from PubMedBiodegradable polyester polyhydroxyalkanoate (PHA) is a promising bioplastic material for industrial use as a replacement for petroleum-based plastics. PHA synthase PhaC forms an active dimer to polymerize acyl moieties from the substrate acyl-coenzyme A (CoA) into PHA polymers. Here we present the crystal structure of the catalytic domain of PhaC from Chromobacterium sp. USM2, bound to CoA. The structure reveals an asymmetric dimer, in which one protomer adopts an open conformation bound to CoA, whereas the other adopts a closed conformation in a CoA-free form. The open conformation is stabilized by the asymmetric dimerization and enables PhaC to accommodate CoA and also to create the product egress path. The bound CoA molecule has its beta-mercaptoethanolamine moiety extended into the active site with the terminal SH group close to active center Cys291, enabling formation of the reaction intermediate by acylation of Cys291. Asymmetric Open-Closed Dimer Mechanism of Polyhydroxyalkanoate Synthase PhaC.,Chek MF, Kim SY, Mori T, Tan HT, Sudesh K, Hakoshima T iScience. 2020 May 22;23(5):101084. doi: 10.1016/j.isci.2020.101084. Epub 2020, Apr 21. PMID:32388399[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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