TY - JOUR T1 - Unique Structure and Stability of HmuY, a Novel Heme-Binding Protein of Porphyromonas gingivalis A1 - Wójtowicz, Halina A1 - Guevara, Tibisay A1 - Tallant, Cynthia A1 - Olczak, Mariusz A1 - Sroka, Aneta A1 - Potempa, Jan A1 - Solà, Maria A1 - Olczak, Teresa A1 - Gomis-Rüth, F. Xavier Y1 - 2009/05/08 N2 - Author Summary Pathogenic bacteria cause infection in humans as found in periodontitis, which is a chronic inflammation of the gums caused by Porphyromonas gingivalis. As part of the infective process, bacteria must acquire nutrients to survive and multiply at the infection site, and among such nutrients is heme. This is an iron-dependent co-factor of several indispensable enzymes and proteins. P. gingivalis liberates heme from host heme-binding proteins through the action of proteases and arranges its transport to the bacterial cell through two proteins, HmuY and HmuR. They grab free heme and transport it across the bacterial membrane into the cell, respectively. This function poses stringent conditions on these proteins regarding stability and resistance toward the host immune system. We report here that HmuY is very stable and that it displays a novel protein fold, which consists only of β-strands. It reminds us of a right hand, whose fingers trap heme. Once heme is bound, HmuY forms tetramers, which have the four heme-binding sites buried and thus protected from competing host heme-binding proteins. This feature also facilitates heme transport to HmuR and into the bacterial cell. All these data may help to develop new antibacterial agents at times in which resistance toward antibiotics, both at intensive healthcare stations and in the community, poses serious challenges to human health. JF - PLOS Pathogens JA - PLOS Pathogens VL - 5 IS - 5 UR - https://doi.org/10.1371/journal.ppat.1000419 SP - e1000419 EP - PB - Public Library of Science M3 - doi:10.1371/journal.ppat.1000419 ER -