AUTHOR=Miao Xinyu , He Jiaojiao , Zhang Liang , Zhao Xinlu , Ge Ruiguang , He Qing-Yu , Sun Xuesong 

TITLE=A Novel Iron Transporter SPD_1590 in Streptococcus pneumoniae Contributing to Bacterial Virulence Properties

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01624

DOI=10.3389/fmicb.2018.01624

ISSN=1664-302X

ABSTRACT=<p><italic>Streptococcus pneumoniae</italic>, a Gram-positive human pathogen, has evolved three main transporters for iron acquisition from the host: PiaABC, PiuABC, and PitABC. Our previous study had shown that the mRNA and protein levels of SPD_1590 are significantly upregulated in the Δ<italic>piuA</italic>/Δ<italic>piaA</italic>/Δ<italic>pitA</italic> triple mutant, suggesting that SPD_1590 might be a novel iron transporter in <italic>S. pneumoniae</italic>. In the present study, using <italic>spd1590</italic>-knockout, -complemented, and -overexpressing strains and the purified SPD_1590 protein, we show that SPD_1590 can bind hemin, probably supplementing the function of PiuABC, to provide the iron necessary for the bacterium. Furthermore, the results of iTRAQ quantitative proteomics and cell-infection studies demonstrate that, similarly to other metal-ion uptake proteins, SPD_1590 is important for bacterial virulence properties. Overall, these results provide a better understanding of the biology of this clinically important bacterium.</p>