Disease relevance of ureB

• Purification of recombinant Helicobacter pylori urease apoenzyme encoded by ureA and ureB [1].
• These data indicate that the ureA and ureB genes encoding H. pylori urease are transcribed and translated in E. coli and that these genes alone are sufficient for the synthesis and assembly of the native size enzyme [1].

High impact information on ureB

• By sequencing the DNA region adjacent to the transposon insertion site two open reading frames, designated ureA and ureB, were identified [2].
• The three subunits of the nickel-containing enzyme are encoded by ureA, ureB, and ureC based on protein structural studies and sequence homology to jack bean urease [3].
• RESULTS: In comparison with the reported corresponding sequences, the nucleotide sequence homology of the cloned ureB gene was from 96.88-97.82% while the homology of its putative amino acid sequence was as high as 99.65-99.82% [4].
• AIM: To demonstrate the effect of lactose as an inducer on expression of the recombinant proteins encoded by Helicobacter pylori ureB and hpaA, and Escherichia coli LTB and LTKA63 genes and to determine the optimal expression parameters [5].
• METHODS: The ureB gene from a clinical Helicobacter pylori (H pylori) strain Y06 and the ltB gene from Escherichia coli (E. coli) strain 44851 were linked into ltB-ureB fusion gene by PCR [6].

Biological context of ureB

• SE5000 containing recombinant H. pylori urease genes was grown in minimal medium containing no amino acids, NiCl2 was added to 0.75 microM, and structural genes ureA and ureB (pHP902) were overexpressed in trans to the complete urease gene cluster (pHP808) [7].
• Introduction of the shuttle vector clone DNA (pBHP489K/AB; 6.7 kb), containing the ureA and ureB genes of H. pylori, into urease-negative mutants of H. pylori led to the restoration of their urease activity [8].
• Ribotyping with this probe demonstrated less diversity among isolates from rhesus monkeys than was reported among isolates of H. pylori from humans, as did RFLP analysis of a PCR fragment of the ureA-ureB gene cluster [9].
• The three accessory genes were able to activate apo-urease in vivo when they were cloned into a compatible expression vector and cotransformed into cells carrying the plasmid containing ureA, ureB, and ureC [3].

References