text_1: The ureABIEFGH gene cluster encodes urease maturation proteins : UreD/UreH, UreE, UreF, and UreG.
text_2: Mutation of Trp 153 in the cytoplasmic constriction site to Ala or Phe decreases the selectivity for urea in comparison with thiourea, suggesting that solute interaction with Trp 153 contributes specificity.