Brucella abortus ure2 region contains an acid-activated urea transporter and a nickel transport system

摘要: Background: Urease is a virulence factor that plays role in the resistance of Brucella to low pH conditions, both vivo and vitro. contains two separate urease gene clusters, ure1 ure2. Although only codes for an active urease, ure2 also transcribed, but its contribution biology unknown. Results: Re-examination locus showed operon includes five genes downstream ureABCEFGDT are orthologs nikKMLQO cluster encoding ECF-type transport system nickel. ureT nikO mutants were constructed analyzed activity acid resistance. A non-polar mutant was unaffected at neutral significantly decreased acidic pH. It survival rate 2 concentration urea when compared wild type. The had all concentrations tested, this phenotype could be reverted by addition nickel growth medium. Conclusions: Based on these results, we concluded acid-activated transporter necessary maximal whose structural subunits encoded exclusively operon. Background catalyzes chemical hydrolysis molecule into CO ammonia. These equilibrate water causing rise Accordingly, bacterial ureases serve main purposes: neutralize provide source assimilable nitrogen.