“…Moreover, heterologous expression and characterization of respective C. trachomatis enzymes in E. coli confirmed that they are functional (Iliffe-Lee & McClarty, 1999). Consistent with the earlier experimental observations (Weiss, 1965;Vender & Moulder, 1967;Weiss & Wilson, 1969), genomic data confirmed that Chlamydiaceae lack a hexokinase gene, as well as substrate-specific components of the phosphotransferase system (PTS; Stephens et al, 1998;Kalman et al, 1999;McClarty, 1999;Read et al, 2000Read et al, , 2003Carlson et al, 2005;Thomson et al, 2005;Azuma et al, 2006;Thomson et al, 2008;Mojica et al, 2011;Voigt et al, 2012). The bacteria thus depend on the import of phosphorylated sugar (D-glucose-6-phosphate) from the host cell cytosol, which is likely accomplished by a sugar-phosphate/inorganic-phosphate antiporter (UhpC; McClarty, 1999), the C. pneumoniae homolog of which has been functionally characterized in E. coli (Schw€ oppe et al, 2002).…”