Identification and characterization of a novel porin family highlights a major difference in the outer membrane of chlamydial symbionts and pathogens

摘要: The Chlamydiae constitute an evolutionary well separated group of intracellular bacteria comprising important pathogens humans as symbionts protozoa. amoeba symbiont Protochlamydia amoebophila lacks a homologue the most abundant outer membrane protein Chlamydiaceae, major MOMP, highlighting difference between environmental chlamydiae and their pathogenic counterparts. We recently identified novel family putative porins encoded in genome P. by silico analysis. Two these proteins, PomS (pc1489) PomT (pc1077), are highly preparations this organism. Here we show that all four members porin toxic when expressed heterologous host Escherichia coli. Immunofluorescence analysis using antibodies against heterologously purified directly from elementary bodies, respectively, demonstrated location both proteins amoebophila. was further confirmed immuno-transmission electron microscopy. could pomS is transcribed, corresponding present throughout complete developmental cycle, suggesting essential role for Lipid bilayer measurements functions with anion-selectivity pore size similar to Chlamydiaceae MOMP. Taken together, our results suggest PomS, possibly concert other family, functional equivalent MOMP This work contributes understanding adaptations symbiotic different eukaryotic hosts.