%0 Journal Article %A Reece, Stephen %A Simmons, Cameron P %A Fitzhenry, Robert J %A Batchelor, Miranda %A Hale, Christine %A Matthews, Stephen %A Phillips, Alan D %A Dougan, Gordon %A Frankel, Gad %T Mutagenesis of conserved tryptophan residues within the receptor-binding domain of intimin: influence on binding activity and virulence %D 2002 %J Microbiology, %V 148 %N 3 %P 657-665 %@ 1465-2080 %R https://doi.org/10.1099/00221287-148-3-657 %K EPEC, EHEC, Tir %K LEE, locus of enterocyte effacement %K Citrobacter rodentium %K EPEC, enteropathogenic Escherichia coli %K A/E lesion, ‘attaching and effacing’ lesion %K EHEC, enterohaemorrhagic Escherichia coli %K MBP, maltose-binding protein %K FAS, fluorescent actin stain %K Tir, translocated intimin receptor %I Microbiology Society, %X Intimate bacterial adhesion to intestinal epithelium is a pathogenic mechanism shared by several human and animal enteric pathogens, including enteropathogenic and enterohaemorrhagic Escherichia coli and Citrobacter rodentium. The proteins directly involved in this process are the outer-membrane adhesion molecule intimin and the translocated intimin receptor, Tir. The receptor-binding activity of intimin resides within the carboxy terminus 280 aa (Int280) of the polypeptide. Four tryptophan residues, W117/776, W136/795, W222/881 and W240/899, are conserved within different Int280 molecules that otherwise show considerable sequence variation. In this study the influence of site-directed mutagenesis of each of the four tryptophan residues on intimin-Tir interactions and on intimin-mediated intimate attachment was determined. The mutant intimins were also studied using a variety of in vitro and in vivo infection models. The results show that all the substitutions modulated intimin activity, although some mutations had more profound effects than others. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-148-3-657