Disease relevance of angH

• We have identified and sequenced an hdc gene in the Vibrio anguillarum plasmid pJM1 which encodes a histidine decarboxylase enzyme and is an essential component for the biosynthesis of anguibactin [1].
• These results indicate that angH is essential for histamine biosynthesis in V. anguillarum, a compound responsible for food poisoning and potentially involved in bacterial virulence [2].
• Escherichia coli strains, which are Hdc negative and do not use histidine as a carbon, nitrogen, and energy source, gave negative results with the differential solid medium and produced only moderate amounts of ammonia when cultured in the presence of excess histidine [3].
• Cloning and sequencing of the histidine decarboxylase gene from Photobacterium phosphoreum and its functional expression in Escherichia coli [4].

High impact information on angH

• A histidine decarboxylase gene encoded by the Vibrio anguillarum plasmid pJM1 is essential for virulence: histamine is a precursor in the biosynthesis of anguibactin [1].
• The role of histidine decarboxylase in biosynthesis of anguibactin was confirmed by the fact that growth under iron starvation was restored by addition of histamine to the medium [1].
• Conversely, histamine was not detected in the culture supernatant of an isogenic V. anguillarum Hdc mutant and the A. baumannii 8399 strain that secretes a catechol siderophore different from anguibactin and acinetobactin [3].
• The iron uptake-deficient phenotype of one of the angH mutants confirmed the location of the mutation and the unique role of this gene in iron acquisition [2].
• Reverse transcription polymerase chain reaction showed that only the wild-type strain expressed angH, while no angH message was detected in the mutants and the plasmidless derivative [2].

Associations of angH with chemical compounds

• However, the role of angH in histamine biosynthesis by this pathogen has not been fully determined [2].
• Thin-layer chromatography of wild-type culture supernatants and beta-galactosidase assays using the isogenic angH mutant demonstrated that the expression of this gene is independent of the histidine concentration of the medium under both iron-rich and iron-limiting conditions [2].

References