Functional organization and regulatory logic of the ped gene cluster in Pseudomonas species

ABSTRACT Pseudomonas species display exceptional metabolic versatility that underpins their ecological success and broad relevance for synthetic biology, environmental microbiology, bioremediation, and bioproduction. A central contributor to this versatility is the ped gene cluster, which encodes pyrroloquinoline quinone (PQQ)-dependent dehydrogenases that catalyze the oxidation of a wide range of alcohols and aldehydes. These enzymes support both assimilation and detoxification processes with high catalytic efficiency. This review compiles current knowledge on genetic organization, enzymatic functions, and multi-level regulation of the ped cluster, with a focus on Pseudomonas putida KT2440 and Pseudomonas aeruginosa PAO1. The roles of regulatory components [e.g., the iron (Fe 2+ )-dependent YiaY dehydrogenase and the hybrid PP_2683 histidine kinase] are examined for their capacity to respond to short-chain alcohols through a complex signal transduction network. Additional genetic elements, including pedF and pedG , along with poorly characterized open reading frames (e.g., pedD , PP_2666 , and PP_2678 ), which support enzymatic maturation, electron flow, and modulation of surface-associated behaviors are likewise considered. Comparative analysis across the Pseudomonas genus showed that ped -like clusters are conserved but display substantial differences in gene content and arrangement, suggesting adaptations to specific ecological contexts. We evaluate these elements in detail to define a reference framework for future mechanistic studies. By bringing together functional and regulatory features of the cluster, our article provides a basis for exploiting the Ped system as a modular platform in applied microbiology. This integrated view aims to guide ongoing and future fundamental and applied research on alcohol oxidation in gram-negative bacteria.