St because it has a high Trp content in the pathogenic Chlamydiaceae is located at the CT645 locus on the lagging strand in C. trachomatis and encodes the cell division protein YlmG/Ycf19. It has an extremely high p/P Trp ratio (4.30) and must have been subject to Chlamydiaceae-specific up-Trp selection, since the homolog in "Ca. Protochlamydia amoebophila" has a p/P Trp ratio of 1.09. No bidirect