Pathway crosstalk between the central metabolic and heme biosynthetic pathways in Phanerochaete chrysosporium

作者：Daisuke Miura, Ryoga Tsurigami, Hiroyuki Kato, Hiroyuki Wariishi, Motoyuki Shimizu · 发表于：Applied Microbiology and Biotechnology · 年份：2024 · DOI：10.1007/s00253-023-12846-0 · 被引用次数：3 · 研究领域：Porphyrin Metabolism and Disorders、Microbial bioremediation and biosurfactants、Microbial Community Ecology and Physiology

Abstract A comprehensive analysis to survey heme-binding proteins produced by the white-rot fungus Phanerochaete chrysosporium was achieved using a biotinylated heme–streptavidin beads system. Mitochondrial citrate synthase (PcCS), glyceraldehyde 3-phosphate dehydrogenase (PcGAPDH), and 2-Cys thioredoxin peroxidase (mammalian HBP23 homolog) were identified as putative heme-binding proteins. Among these, PcCS and PcGAPDH were further characterized using heterologously expressed recombinant proteins . Difference spectra of PcCS titrated with hemin exhibited an increase in the Soret absorbance at 414 nm, suggesting that the axial ligand of the heme is a His residue. The activity of PcCS was strongly inhibited by hemin with Ki oxaloacetate of 8.7 μM and Ki acetyl-CoA of 5.8 μM. Since the final step of heme biosynthesis occurred at the mitochondrial inner membrane, the inhibition of PcCS by heme is thought to be a physiological event. The inhibitory mode of the heme was similar to that of CoA analogues, suggesting that heme binds to PcCS at His 347 at the AcCoA–CoA binding site, which was supported by the homology model of PcCS. PcGAPDH was also inhibited by heme, with a lower concentration than that for PcCS. This might be caused by the different location of these enzymes. From the integration of these phenomena, it was concluded that metabolic regulations by heme in the central metabolic and heme synthetic pathways occurred in the mitochondria and cytosol. This novel pathway cro...