PHA synthase (PhaC): interpreting the functions of bioplastic-producing enzyme from a structural perspective

摘要: Polyhydroxyalkanoates (PHAs) are biopolymers synthesized by a wide range of bacteria, which serve as promising candidate in replacing some conventional petrochemical-based plastics. PHA synthase (PhaC) is the key enzyme polymerization PHA, and crystal structures were successfully determined using catalytic domain PhaC from Cupriavidus necator (PhaCCn-CAT) Chromobacterium sp. USM2 (PhaCCs-CAT). Here, we review beneficial mutations discovered PhaCs structural perspective. The comparison residues involved mutation reveals that near to triad, but not inside pocket. For instance, Ala510 PhaCCn His508 may be open-close regulation, presumably play an important role substrate specificity activity. In class II PhaC1 Pseudomonas 61-3 (PhaC1Ps), Ser325 stabilizes cysteine through hydrogen bonding. Another residue, Gln508 PhaC1Ps located conserved hydrophobic pocket next Asp His. A I, II-conserved Phe420 one dimerization its serine greatly reduced lag phase. current analysis shows Phe362 Phe518 Aeromonas caviae (PhaCAc) assisting dimer formation maintaining integrity core beta-sheet, respectively. structure-function relationship discussed this will valuable reference for future protein engineering works enhance performance produce novel biopolymers.