Analysis of gene expression in Porphyromonas gingivalis hemH and ihtB deletion mutant strains grown under heme- and iron-replete conditions (RNA-seq analysis)
Porphyromonas gingivalis is a keystone pathogen responsible for oral microbiome dysbiosis, the development of periodontal disease, and may be involved in the development of systemic comorbidities. As a heme auxotroph, P. gingivalis relies on host hemoproteins as its primary sources of heme and iron. Although heme acquisition in P. gingivalis is relatively well characterized, considerably less is known about its pathways for iron uptake and the regulation of iron and heme homeostasis. P. gingivalis encodes four enzymes associated with the heme biosynthesis pathway, namely HemD, HemN, HemG, and HemH. HemH is a ferrochelatase responsible for the final step of heme biosynthesis, catalyzing the insertion of ferrous iron (Fe²?) into protoporphyrin IX. In addition, P. gingivalis expresses the Iht system, which plays a role in iron/heme utilization. One of its components, IhtB, is a heme-binding protein homologous to CbiK cobaltochelatases. Based on this homology, IhtB is hypothesized to function as a reverse ferrochelatase, facilitating the removal of iron from heme and thereby contributing to iron acquisition. This study aimed to investigate the effect of ihtB and hemH gene deletions on P. gingivalis gene expression under heme- and iron-replete conditions, to elucidate the roles of IhtB and HemH chelatases in heme and iron homeostasis.
Porphyromonas gingivalis is a keystone pathogen responsible for oral microbiome dysbiosis, the development of periodontal disease, and may be involved in the development of systemic comorbidities. As a heme auxotroph, P. gingivalis relies on host hemoproteins as its primary sources of heme and iron. Although heme acquisition in P. gingivalis is relatively well characterized, considerably less is known about its pathways for iron uptake and the regulation of iron and heme homeostasis. P. gingivalis encodes four enzymes associated with the heme biosynthesis pathway, namely HemD, HemN, HemG, and HemH. HemH is a ferrochelatase responsible for the final step of heme biosynthesis, catalyzing the insertion of ferrous iron (Fe²?) into protoporphyrin IX. In addition, P. gingivalis expresses the Iht system, which plays a role in iron/heme utilization. One of its components, IhtB, is a heme-binding protein homologous to CbiK cobaltochelatases. Based on this homology, IhtB is hypothesized to function as a reverse ferrochelatase, facilitating the removal of iron from heme and thereby contributing to iron acquisition. This study aimed to investigate the effect of ihtB and hemH gene deletions on P. gingivalis gene expression under heme- and iron-replete conditions, to elucidate the roles of IhtB and HemH chelatases in heme and iron homeostasis.
European Bioinformatics Institute