uptake of biotin by chlamydia spp. through the use of a bacterial transporter (bioy) and a host-cell transporter (smvt)吸收的生物素衣原体种虫害通过使用细菌运输车(bioy)和宿主细胞转运体(smvt).pdf

Uptake of Biotin by Chlamydia Spp. through the Use of a Bacterial Transporter (BioY) and a Host-Cell Transporter (SMVT) 1 ´ 2 2 2 Derek J. Fisher , Reinaldo E. Fernandez , Nancy E. Adams , Anthony T. Maurelli * 1 Department of Microbiology, Southern Illinois University, Carbondale, Illinois, United States of America, 2 Department of Microbiology and Immunology, F. Edward ´ Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America Abstract Chlamydia spp. are obligate intracellular Gram-negative bacterial pathogens that cause disease in humans and animals. Minor variations in metabolic capacity between species have been causally linked to host and tissue tropisms. Analysis of the highly conserved genomes of Chlamydia spp. reveals divergence in the metabolism of the essential vitamin biotin with genes for either synthesis (bioF_2ADB) and/or transport (bioY). Streptavidin blotting confirmed the presence of a single biotinylated protein in Chlamydia. As a first step in unraveling the need for divergent biotin acquisition strategies, we examined BioY (CTL0613) from C. trachomatis 434/Bu which is annotated as an S component of the type II energy coupling- factor transporters (ECF). Type II ECFs are typically composed of a transport specific component (S) and a chromosomally unlinked energy module (AT). Intriguingly, Chlamydia lack recognizable AT modules. Using 3H-biotin and recombinant E. coli expressing CTL0613, we demonstrated that biotin was transported with high affinity (a property of Type II ECFs previously shown to require an AT module) and capacity (apparent K(m) of 3.35 nM and V(max) of 55.1 pmol 6min21 6mg21). Since Ch