phaE

PhaE is a gene name used for a protein found in several polyhydroxyalkanoate (PHA) producing bacteria. In these organisms, PhaE encodes a small subunit that is part of the PHA synthase complex, typically alongside the core enzyme PhaC. The precise role of PhaE varies by species but is commonly described as contributing to the stability or activity of the synthase, potentially aiding substrate access or product release, and in some cases influencing the polymer’s chain length and monomer composition.

Genomic context places phaE within or near pha operons such as phaA, phaB, and phaC. Homologs of PhaE are found in diverse Gram-negative bacteria that synthesize PHAs, though not all PHA producers carry a phaE gene. Structural information is limited; many PhaE proteins are predicted to be peripheral or membrane-associated, lacking obvious transmembrane segments, with interactions inferred from genetic and biochemical studies.

From an applied perspective, PhaE is of interest in metabolic engineering for bioplastic production. Modulation of phaE expression or function can affect PHA yield and composition, depending on the host and substrate, although the effects are context-dependent.

See also polyhydroxyalkanoate biosynthesis, PhaA, PhaB, PhaC, and PhaP.