Macrophage infectivity potentiators (Mips) are FKBP brooklyn bridge side view domain-containing proteins reported as virulence factors in several human pathogens, such as members of genera Legionella, Salmonella and Chlamydia.The putative peptidyl-prolyl cis-trans isomerase (PPIase) encoded by XC2699 of the plant bacterial pathogen Xanthomonas campestris pv.campestris 8004 exhibits a 49% similarity at the aminoacid level to the Mip protein of Legionella pneumophila.
This mip-like gene, XC2699, was overexpressed in Es-cherichia coli and the purified (His)6-tagged Mip-like protein encoded by XC2699 exhibited a PPIase activity specifically inhibited by FK-506.A mutation in the mip-like gene XC2699 led to significant reductions in virulence and replication capacity in the host plant Chinese radish (Raphanus sativus L.var.
radiculus Pers.).Furthermore, the production of exopolysaccharide and the activity of extracellular proteases, virulence factors X.
campestris pv.campestris, were significantly decreased in the mip-like mutant.These results reveal that the mip-like gene is involved in the pathogenesis of X.
campestris pv.campestris through an effect on the production of these a&d ej-123 virulence factors.