Lh. Saltman et al., A REGION OF THE YERSINIA-PSEUDOTUBERCULOSIS INVASIN PROTEIN THAT CONTRIBUTES TO HIGH-AFFINITY BINDING TO INTEGRIN RECEPTORS, The Journal of biological chemistry, 271(38), 1996, pp. 23438-23444
The entry of Yersinia pseudotuberculosis into cultured mammalian cells
is mediated by the bacterial protein invasin. The mammalian receptors
for invasin are five beta(1) chain integrins. Site directed mutagenes
is of the aspartate and lysine residues in the 192-amino acid integrin
binding domain of invasin was performed to identify regions, in addit
ion to the previously characterized 903-913 region, that are important
for integrin binding. One mutation, D811A, resulted in depressed abil
ity of invasin to bind purified alpha(5) beta(1) and to promote bacter
ial entry. Further mutational analysis of Asp-811 indicated that an ox
ygen-containing side chain is required at this position, A second near
by residue, Phe-808, was also shown to be important for integrin bindi
ng, as an alanine substitution at this site had properties similar to
the Asp-811 mutation. This mutational analysis has therefore identifie
d a second region that, in conjunction with residues 903-913, is requi
red for wild type levels of integrin binding. The contribution to bind
ing by two noncontiguous sites in the primary sequence parallels resul
ts that indicate two domains of fibronectin are involved in integrin b
inding.