Urease of Corynebacterium glutamicum: organization of corresponding genes and investigation of activity.

The Corynebacterium glutamicum genes encoding urease were isolated and sequenced. While ureA, ureB and ureC are encoding structural subunits of urease, ureE, ureF, ureG and ureD are encoding accessory proteins. As deduced from DNA sequence analyses, the ure genes are transcriptionally coupled, this was proven by RT-PCR at least for ureABC. Gene disruption experiments revealed that both structural (UreC) and accessory proteins (UreD) are indispensable for urease activity and growth on urea. Urease activity was determined in different Corynebacterium species after growth in various media. While the regulation patterns observed revealed species-specific differences, in general urease activity is induced upon nitrogen starvation. As in mycobacteria, in corynebacteria urease activity was highest in a pathogenic species and might also play a role in host-pathogen interaction.