Brian Cook

Subtomogram Averaging of a mitochondrially co-translating ribosome

Happy to share that the final version of record for our (
@nanigrotjahn.bsky.social) #teamtomo mitochondrial cotranslation story is online at @jcb.org! We combined STA with surface morphometrics to learn how ribosomes bind to and alter mitochondrial membranes in yeast.

rupress.org/jcb/article/...

07.03.2025 00:32 — 👍 107    🔁 28    💬 1    📌 0

Structural basis for the conformational protection of nitrogenase from O2 - Nature Cryo-electron microscopy of Azotobacter vinelandii FeSII–nitrogenase reveals a core complex of molybdenum–iron proteins (MoFePs), iron proteins (FePs) and FeSII, in which FeSII mediates interactions with MoFeP and FeP to position their FeS clusters in catalytically inactive but O2-protected states.

Nature research paper: Structural basis for the conformational protection of nitrogenase from O2

https://go.nature.com/4aiD344

13.01.2025 20:04 — 👍 32    🔁 7    💬 0    📌 0

Awesome work from Sarah, @bcryo.bsky.social and friends in the Herzik Lab! It was cool to see this come together in such a short time.

09.01.2025 04:39 — 👍 2    🔁 1    💬 0    📌 0

Structural basis for the conformational protection of nitrogenase from O2 - Nature Cryo-electron microscopy of Azotobacter vinelandii FeSII–nitrogenase reveals a core complex of molybdenum–iron proteins (MoFePs), iron proteins (FePs) and FeSII, in which FeSII mediates interactions w...

The paper can be found here: www.nature.com/articles/s41...

08.01.2025 23:13 — 👍 2    🔁 1    💬 1    📌 0

7) This was an exciting study led by Sarah Narehood in collaboration with Suppachai Srisantitham, Vanessa Eng, Angela Shiau, Kelly McGuire, David Britt. #cryoEM #cryoSPARC #Nitrogenase #HerizkLab @nature.com @sptlabtech.bsky.social @structurabio.bsky.social #UCSDChemBioChem #anaerobicEM

08.01.2025 23:09 — 👍 5    🔁 0    💬 1    📌 0

6) We were able to achieve these structures using our newly developed (an)aerobic freezing protocol using the SPT chameleon. This allowed us to generate high quality girds with thin ice without having to be in an anaerobic chamber!
www.biorxiv.org/content/10.1...

08.01.2025 23:08 — 👍 9    🔁 4    💬 2    📌 0

5) Our structures combined with our analytical ultracentrifugation and EPR experiments allow us to propose a mechanism by which these oxygen protecting complexes and filaments form in oxidizing conditions, protecting MoFeP and FeP, and disassemble in reducing conditions.

08.01.2025 23:07 — 👍 4    🔁 1    💬 1    📌 0

4) Surprisingly, the binding of Shethna occurs at the catalytic interface of both MoFeP and FeP! Preventing nitrogen fixation while also protecting the oxygen sensitive metal clusters harbored by both MoFeP and FeP.

08.01.2025 23:05 — 👍 2    🔁 1    💬 1    📌 0

3) We show that Shetna is capable of binding both the catalytic (MoFeP) and reductant (FeP) subunits, creating oxygen protecting complex. Fascinatingly, this complex is capable of forming higher order complexes and ultimately filaments!

08.01.2025 22:59 — 👍 5    🔁 1    💬 1    📌 0

2) The only known nitrogen fixing enzyme employed by microbes is nitrogenase, a highly oxygen sensitive protein complex. In this study we were able to determine multiple structures of Nitrogenase in complex with the small protein Shethna (FeSII), solving a decades long mystery.

08.01.2025 22:54 — 👍 1    🔁 0    💬 1    📌 0

1) Since I am the only Herzik lab member on @bsky.app, I get the privilege to announce our most recent publication from the Herzik/Tezcan labs. I got the wonderful opportunity to contribute on the cryoEM study of the oxygen protection mechansim employed by cells to protect Nitrogenase!

08.01.2025 22:54 — 👍 60    🔁 18    💬 4    📌 1