[P002] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P01-136] Dual Irr-like Fur regulators couple iron economy to C1 metabolism in a type II methanotroph

○Hyeonwoo Mun¹, Chanju Kang¹, Sukjae Han², Junyeob Kim³, Hanbit Song⁴, Sangwoo Seo^1,2,4,5,6 (1. Sch. Chem. Biol. Eng., Seoul Natl. Univ. (Korea), 2. Interdiscip. Program Bioeng., Seoul Natl. Univ. (Korea), 3. Clean Energy Res. Cent., KIST (Korea), 4. Inst. Chem. Process., Seoul Natl. Univ. (Korea), 5. Bio-MAX Inst., Seoul Natl. Univ. (Korea), 6. Inst. Bioeng., Seoul Natl. Univ. (Korea))

Keywords:

Methylocystis sp.MJC1,Regulatory network,Fur homologs,Iron-responsive regulation

Methanotrophs oxidize methane through metal-dependent redox networks in which iron availability can constrain respiratory electron transfer, yet iron-responsive regulation in these specialists remains poorly defined. In the type II methanotroph Methylocystis sp. MJC1, we show that two Irr-like Fur homologs are functionally separated within an organized iron-response program. Condition-specific ChIP–exo and RNA-seq of Δfur1, Δfur2, and Δfur1Δfur2 strains reveal a division of labor: Fur2 displays broad ChIP-exo enrichment across iron regimes and directly governs core iron-economy functions, including iron acquisition and storage, with additional non-canonical regulation consistent with direct activation of siderophore uptake and bacterioferritin loci. In contrast, Fur1 is selectively engaged under iron limitation, directly repressing pmoC (a subunit of particulate methane monooxygenase) and coordinating a broader adaptive program. Consistent with this logic, iron limitation is accompanied by coordinated transcriptional downregulation of methane oxidation genes and serine-cycle assimilation modules, indicating reduced investment in C1 flux when iron is scarce. Together, these data define a division-of-labor regulatory circuit in which two Irr-like Fur homologs couple iron economy to methane-based metabolism in a type II methanotroph.