6K3C

Crystal structure of class I PHA synthase (PhaC) mutant from Chromobacterium sp. USM2 bound to Coenzyme A.

Summary for 6K3C

• Entry DOI: 10.2210/pdb6k3c/pdb
• Descriptor: Intracellular polyhydroxyalkanoate synthase, COENZYME A (3 entities in total)
• Functional Keywords: bioplastic synthase, catalytic domain, coa binding., biosynthetic protein, open conformation, open-closed dimer
• Biological source: Chromobacterium sp. USM2
• Total number of polymer chains: 2
• Total formula weight: 88424.35

Authors

Chek, M.F.,Kim, S.Y.,Mori, T.,Hakoshima, T. (deposition date: 2019-05-17, release date: 2020-04-29, Last modification date: 2023-11-22)

Primary citation

Chek, M.F.,Kim, S.Y.,Mori, T.,Tan, H.T.,Sudesh, K.,Hakoshima, T.
Asymmetric Open-Closed Dimer Mechanism of Polyhydroxyalkanoate Synthase PhaC.
Iscience, 23:101084-101084, 2020

PubMed Abstract: Biodegradable 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 β-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.

PubMed: 32388399
DOI: 10.1016/j.isci.2020.101084

Experimental method

X-RAY DIFFRACTION (3.074 Å)