Very proud to share the first fruits of my postdoc at @_Murphy_Lab @MPIbp, in which we resolved the structure of S. pneumoniae NADPH-oxidase (46 kDa!! membrane protein, No nanobodies!) using cryo-EM!!! (See thread below)

🚨 new paper alert 🚨 We present a method for designing protein nanoparticles with two unique faces that can bring together distinct biological targets at controlled distances! This project was led by Dr. Sanela Rankovic is out now in Nature Materials: https://t.co/Vkxk9N9wfT

The recently discovered giant virus PelV-1 has a tail of unprecedented length. Learn more: https://t.co/dGFUMjaXlL @NewsfromScience

Electron flow in hydrogenotrophic methanogens under nickel limitation

Structural basis for TORC2 activation https://t.co/zYjVhtuSdK #biorxiv_biochem

📢 A team led by Seigo Shima has revealed that #methane producing #microbes can reduce their need for #nickel when levels are low. The study sheds new light on the ecology of #methanogens and their impact on #climatechange. https://t.co/JHCauzQkCU https://t.co/ahj10mZVjH

We also want to thank the @MPIbp electron microscopy facility, especially @sonjawelsch and Mark Linder, for their invaluable help with data collection and microscope setup. We reached up to 1.8 Å resolution for Hdr with this one!

This project is a collaboration between Seigo Shima, @nmura123, @protasov_evgeni, Masanori Kaneko and Jörg Kahnt from @mpi_marburg and @_Murphy_Lab from @MPIbp. Many thanks also to @greeninglab and the other reviewers for helping improve the manuscript.

Elp and Hmd are conserved in many CO₂-reducing hydrogenotrophic #methanogens, suggesting that the discovered #methanogenesis pathway is common and occurs when Ni becomes limited. Such a shift allows them to adapt to ever-changing conditions and highlights their flexibility.

Using 3D classification followed by focused refinements allowed us to resolve two clear conformational states of ElpABC-HdrA that seem to play a role in gating electron flow for flavin-based electron bifurcation.

Using enzyme assays and #CryoEM, we discovered that ElpABC subunits, like MvhAGD, form a complex with heterodisulfide reductase (Hdr). This revealed that electrons for CO₂ fixation came exclusively from reduced coenzyme F420 — not H₂!

But what happened to the Mvh subunits? How could CO₂ fixation via flavin-based electron bifurcation proceed under nickel-limited conditions?

Therefore, proteomics was suggesting that hydrogenotrophic #methanogens switch from [NiFe] #hydrogenases to the [Fe] #hydrogenase Hmd, likely as a strategy to conserve precious Ni for another #methanogenesis enzyme that cannot be replaced — Mcr.

Three of these proteins were part of the same operon and encoded proteins homologous to formate dehydrogenase (but missing the active site!), F420H2 dehydrogenase and 2Fe2S-binding protein MvhD. We named these proteins Electron-donating proteins ElpA, B and C.

However, the levels of the [Fe] #hydrogenase Hmd were increased. But other proteins were enriched too…

Strikingly, under Ni limitation, quantitative proteomics analysis using iBAQ revealed a huge reduction of the levels of the [NiFe]-hydrogenases Frh and Mvh that are central to the textbook pathway of methanogenesis.

Therefore, we wondered which protein complexes help Methanothermobacter marburgensisgrow under nutrient-restricted conditions, including concentrations of metal ions like iron and nickel more similar to those found in certain natural environments.

Methanogens produce most of the #GreenHouseGas methane, which significantly contributes to #ClimateChange. However, most of our knowledge about methanogens comes from experiments under laboratory conditions that differ greatly from those found in nature.

I'm excited to share our new publication in @Nature! We showed that under Ni-limited conditions, similar to those in nature, #methanogens shift electron flow from [NiFe]- to [Fe]-hydrogenase Hmd with the help of a newly discovered protein complex, Elp. https://t.co/DuOBEBR7To

In what may be one of Earth’s craziest forms of mimicry, researchers in 2023 reported a species of rove beetle that grows a termite puppet on its back to fool real termites into feeding it. Learn more during #InsectWeek: https://t.co/DGNVVL0Pjz

@rcastellsg @PABLOSANSEGUND3 Roger Castell-Graells, procedente de @UCLA, Pablo San Segundo y Laura Pérez-Chirinos se han incorporado al #CNIOStopCancer como parte del programa 'Construyendo la Generación IA' de la iniciativa #GeneraciónD, de @redpuntoes, @mintradigital y @cienciagob https://t.co/GPCfAmf69l