nahH

NahH is a gene symbol used in multiple organisms, most often in bacteria involved in aromatic hydrocarbon degradation. Because gene naming can vary between species and annotation projects, nahH does not designate a single universal protein with a defined function. In the context of naphthalene catabolism in Pseudomonas and related bacteria, nahH has been listed in some operons as encoding a component of the naphthalene degradation pathway, but the precise enzymatic role can differ by strain. Consequently, in different genomes the predicted product of nahH may be described as a subunit of a dioxygenase, a dehydrogenase, or another enzyme associated with converting naphthalene-derived intermediates toward central metabolism.

Function and characterization, when available, are typically obtained from genome annotations and experimental studies on the organism in question. In many cases nahH is discussed alongside other nah genes that form part of the naphthalene utilization cluster, which governs uptake, initial oxidation, ring cleavage, and further processing of degradation intermediates. Regulatory aspects also vary; expression is commonly inducible by naphthalene or related hydrocarbons and may involve nearby transcriptional regulators, such as those of the LysR or AraC families, depending on the organism.

Because gene names can be reused across taxa and annotations change with new evidence, researchers seeking the function of nahH should consult the specific genome or plasmid annotation for the organism and strain of interest. Cross-referencing with curated databases and primary literature is recommended for precise functional assignment.