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John Helmann

@johnhelmann.bsky.social

2.1K followers 618 following 48 posts

Professor at Cornell Univ. Bacillus subtilis physiology and stress responses (metal homeostasis, redox stress, antibiotic resistance & cell envelope). EIC of Mol Microbiol.

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John Helmann @johnhelmann.bsky.social · 14/08/2025

The B. subtilis histidine-containing phosphocarrier protein (HPr) supports PTS-sugar import, interacts with GAPDH, and helps mediate carbon catabolite repression (CCR). Here, a mutant HPr protein is shown to alleviate metabolic intoxication in a cpgA mutant. journals.asm.org/doi/10.1128/...

A metabolic diagram illustrating various ways the HPr protein interacts with other proteins to affect metabolism.

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John Helmann @johnhelmann.bsky.social · 03/07/2025

A new paper led by Ahmed Gaballa and Yesha Patel explores the pathways that reduce the dithiolopyrrolone (DTP) antibiotic thiolutin in B. subtilis. The active dithiol chelates intracellular Zn ions to impede growth. #MicroSky #Zinc #Antibiotics journals.asm.org/doi/10.1128/...

Schematic of reduction pathways for thiolutin, bacillithiol, and TrxAB

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John Helmann @johnhelmann.bsky.social · 05/03/2025

This new cryoEM structure can be viewed in the context of results published previously by Huang et al. onlinelibrary.wiley.com/doi/10.1111/... MntR represses uptake genes (mntH, mntA) and activates efflux genes (mneP/S). The latter occurs with higher Mn and with higher cooperativity. #MicroSky

graph showing the concentrations of Mn(II) needed to elicit repression of Mn uptake genes in B. subtilis compared to the higher concentration (and greater cooperativity) needed for activation of efflux genes.

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John Helmann @johnhelmann.bsky.social · 06/01/2025

Want to hear some great talks about Bacterial Locomotion and Signal Transduction? The BLAST conference (Jan. 19-24) has a "virtual" option this year (for a nominal fee). More than 50 talks and 100 posters! blastscience.regfox.com/blast-xviii-... Registration deadline is Friday, Jan 10!

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