PhzA

PhzA, short for phenazine biosynthesis protein A, is a gene that encodes a component of the phenazine biosynthesis pathway in certain bacteria, most notably within Pseudomonas species. It is typically part of the phzA–phzG gene cluster that governs the production of phenazine compounds, a class of redox-active secondary metabolites.

In its presumed role, PhzA participates in the early steps of converting chorismate-derived intermediates into phenazine-1-carboxylic acid (PCA), the core precursor to several phenazine pigments. PhzA often functions together with other proteins in a multi-enzyme complex, such as PhzB and additional phz gene products, with the exact enzymatic activity and mechanism varying among species. The pathway ultimately yields PCA, which can be modified to form derivatives like pyocyanin in some strains of Pseudomonas aeruginosa.

Expression of phzA and the surrounding phzA–phzG cluster is influenced by regulatory networks that respond to environmental conditions, redox status, and population density (quorum sensing). Phenazine production can affect microbial competition, biofilm development, and, in pathogenic contexts, virulence, as observed in P. aeruginosa where phenazines contribute to redox cycling and host interactions.

Distribution and organization of phzA homologs have been observed in several Gram-negative bacteria beyond Pseudomonas, though the operon structure and regulatory controls may differ. Functional studies often involve gene disruption to assess impacts on phenazine production and related physiological traits.