Involved in the biosynthesis of 4-methoxy-2,2'-bipyrrole-5-carbaldehyde (MBC), one of the terminal products involved in the biosynthesis of the red antibiotic prodigiosin (Pig). Carrier of the L-malonyl group (malonyl-S-PigH), which is decarboxylated by PigJ to yield a C2 carbanion acetyl-S-PigH. Then the pyrrolyl group of pyrrolyl-S-cysteinyl PigJ intermediate is captured by the C2 carbanion acetyl-S-PigH to yield the pyrrolyl-beta-ketoacyl-S-PigH. In the last step, PigH catalyzes the decarboxylative condensation between the pyrrolyl-beta-ketoacyl (pyrrolyl-beta-ketoacyl-S-PigH) and L-serine to yield 4-hydroxy-2,2'-bipyrrole-5-methanol (HBM). Antibiotic biosynthesis; prodigiosin biosynthesis. Cells with an insertion in the ACP domain of this gene show an white phenotype and produce 2-methyl-3-n-amyl-pyrrole (MAP) but not prodigiosin. Cells with an insertion in the aminotransferase domain of this gene show a light pink phenotype and produce less prodigiosin than the wild-type.