Two PHA synthase genes, phaC1 and phaC2, have been identified
and characterized in Pseudomonas species (Prieto et al., 1999); they
are separated by the phaZ gene, which encodes PHA depolymerase.
The mcl-PHA biosynthesis gene locus includes also phaD, which
encodes a putative transcriptional regulator of the TetR family with
an important role in polyhydroxyalkanoates biosynthesis (Klinke
et al., 2000). Finally, the genes phaF and phaI which are transcribed
in the opposite direction, encode polyhydroxyalkanoate
granule associated proteins. PhaF has also been considered as a
negative regulator of PHA biosynthesis genes (Prieto et al., 1999).