John Helmann

For those interested in further reading, the studies establishing the triplet nature of the genetic code were also reviewed by both Benzer and Crick in two 1962 Scientific American articles -- both worth a read!
www.jstor.org/stable/24937...
www.jstor.org/stable/24936...

See our @natmicrobiol.nature.com News&Views on the publication from Yun Chen laboratory

A rapid writing exercise for María Negre Rodríguez, a PhD student in my group

Ecological function of phenazine in soil
www.nature.com/articles/s41...

#MicrobiomeEcology at #LeidenBiology

🚨 New Preprint Alert 🚨

Our latest work, A Zur-dependent regulatory RNA involved in maintaining zinc homeostasis in Staphylococcus aureus, is now live on bioRxiv! 🧬🦠📄

Check it out here: www.biorxiv.org/content/10.1...

Monitoring single cell bioenergetic status and cell lysis in dense and differentiating Bacillus subtilis cultures Bacillus subtilis is a major model organism for studying population heterogeneity in clonal bacterial cultures due to its high genetic tractability and ability to differentiate into subpopulations wit...

A new methods paper from us, this time with a focus on reliable monitoring membrane potential and cell lysis at different growth stages and cell densities. Also, note the surprisingly high level of background lysis in seemingly healthy B. subtilis cultures.
www.biorxiv.org/content/10.1...

RagB stimulates the activity of the peptidoglycan polymerase RodA in Bacillus subtilis | EMBO reports imageimageRagB regulates the SEDS protein RodA in Bacillus subtilis, by interacting with RodA and by stimulating its activity. This regulation is essential for cell wall synthesis, especially when Cla...

RagB stimulates the activity of the peptidoglycan polymerase RodA in Bacillus subtilis

[RagB = YrrS]

@emboreports.org by Frédérique Pompeo et al

www.embopress.org/doi/full/10....

A ptsH mutation suppresses growth defects and antibiotic sensitivity in a cpgA mutant defective in metabolite proofreading | Journal of Bacteriology Metabolism relies on the concerted action of hundreds of enzymes, many of which have some activity with non-canonical substrates. The resulting reactions constitute an often-ignored underground metabolism. Glyceraldehyde-3-phosphate dehydrogenase ...

A ptsH mutation (encoding the HPr-G54D variant) suppresses growth defects and antibiotic sensitivity in a Bacillus subtilis cpgA mutant defective in metabolite proofreading!

Where? In Journal of Bacteriology!

🫳 journals.asm.org/doi/10.1128/...

#subtiwiki #subtilis #CCR

Elio Schaechter was one of my heroes. His 1958 paper with Ole Maaløe and Niels Kjeldgaard (fondly known as “SMK”) is a North Star for so much work in my group. A wonderful scientist, great communicator, and a very kind person. May his memory be a blessing.

Archaea produce peptidoglycan hydrolases that kill bacteria Archaea regularly interact with bacteria but reports of archaea killing bacteria are very rare. This study shows that many archaea encode peptidoglycan hydrolases, which specifically target bacterial ...

This first-author publication is my… first! Archaea kill bacteria by targeting their Achilles’ heel: peptidoglycan. Big shoutout to @ahocher.bsky.social‬, @valeriesoo.bsky.social‬, Pauline Misson, @tobiaswarnecke.bsky.social‬ and MRC LMS Proteomics. A thread 🔽
journals.plos.org/plosbiology/...

Comprehensive mapping of transcription terminator Rho utilization (Rut) sites across the Bacillus subtilis genome Abstract. Recent evidence indicates that the bacterial Rho helicase regulates Bacillus subtilis gene expression in a growth-dependent manner. This regulati

New cool work from French friends and colleagues: identification of Rho termination sites in B. subtilis! academic.oup.com/nar/article/...

#SubtiWiki @narjournal.bsky.social @inrae-france.bsky.social

This paper was led by Dr. Ankita Sachla with contributions from current sr. res. assoc. Ahmed Gaballa and former undergraduate student Diana Herrera (Cornell '19; yes.... this took a while).

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

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/...

Thanks Christoph!

Thanks Peter!

Thanks Betül! I hope your students find this helpful.

Microbial metal physiology: ions to ecosystems Nature Reviews Microbiology - Metal ions are required for all cells, and their homeostasis relies on ancient mechanisms that facilitate their import, distribution and storage. In this Review,...

Metal ions are universally required for life, and many of the foundational principles of metal homeostasis have emerged from studies of microbial systems. In this review, I provide a introductory overview targeted to those new to the field.
#MicroSky #Metals

rdcu.be/eycU2

Copper acquisition in Bacillus subtilis involves Cu(II) exchange between YcnI and YcnJ The transition metal copper is biologically essential across all three domains of life. Several copper-dependent proteins and enzymes produced by the Gram-positive bacterium Bacillus subtilis have bee...

Copper acquisition in Bacillus subtilis involves Cu(II) exchange between YcnI and YcnJ

#JBiolChem from @fisherlab.bsky.social
with @johnhelmann.bsky.social

www.jbc.org/article/S002...

Now published, congrats Bevika, Kinki, Vincent, Florian and Paddy! #MicroSky
www.nature.com/articles/s41...

must-read for phageophiles 👇 from sigal ben-yehuda's lab

"𝗬𝗷𝗯𝗛 𝗮𝗻𝗱 𝘁𝗵𝗲 𝗱𝗶𝘃𝗶𝘀𝗶𝗼𝗻 𝗺𝗮𝗰𝗵𝗶𝗻𝗲𝗿𝘆 𝗷𝗼𝗶𝗻𝘁𝗹𝘆 𝗮𝗰𝘁 𝘁𝗼 𝗰𝗼𝗻𝗳𝗶𝗻𝗲 𝗽𝗵𝗮𝗴𝗲 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁𝘀" in Gram-positives (𝘉. 𝘴𝘶𝘣𝘵𝘪𝘭𝘪𝘴)

🙏 @bacteriophile.bsky.social for pointing this out

#PhageSky #MicroSky

Happy to share this detective work by Rune Overlund Stannius now published in #mSystems

phenotype+genomes▶️GWAS▶️gene cluster for pigment production

Identification of widely conserved biosynthetic gene cluster involved in pigment production of Bacillus subtilis
journals.asm.org/doi/10.1128/...

Schematic of reduction pathways for thiolutin, bacillithiol, and TrxAB

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/...

The iron chelator pulcherriminic acid mediates the light response in Bacillus subtilis biofilms - Nature Communications Non-photosynthetic bacteria often respond to changes in light through the action of photoreceptor proteins. Here, Kobayashi et al. show that Bacillus subtilis biofilms display light responses that dep...

The iron chelator pulcherriminic acid mediates the light response in Bacillus subtilis biofilms

@natcomms.nature.com by Kazuo Kobayashi and colleagues

www.nature.com/articles/s41...

Cyclic Di‐AMP Affects Cell Membrane Integrity of Streptococcus pneumoniae When Streptococcus pneumoniae produces low amounts of the second messenger cyclic di-AMP (c-di-AMP), they do not survive in the presence of competence-stimulating peptide (CSP), which is used for tra...

Tiffany Zarrella et al. provide new insights into the role of the bacterial second messenger cyclic di-adenosine monophosphate (c-di-AMP) in maintaining cell envelope homeostasis in Streptococcus pneumoniae.
#MicroSky #cyclic-di-AMP
onlinelibrary.wiley.com/doi/10.1111/...

Cyclic Di‐AMP Affects Cell Membrane Integrity of Streptococcus pneumoniae When Streptococcus pneumoniae produces low amounts of the second messenger cyclic di-AMP (c-di-AMP), they do not survive in the presence of competence-stimulating peptide (CSP), which is used for tra...

👉 Cyclic Di-AMP Affects Cell Membrane Integrity of Streptococcus pneumoniae!

Molecular Microbiology | Microbiology Journal | Wiley Online Library onlinelibrary.wiley.com/doi/10.1111/...

#cdiAMPl @molecularmicro.bsky.social

Staphylococcus aureus COL: An Atypical Model Strain of MRSA That Exhibits Slow Growth and Antibiotic Tolerance due to a Mutation in PRPP Synthetase COL is an unusual “model” strain of Staphylococcus aureus that exhibits slow growth and multidrug antibiotic tolerance. This phenotype is primarily due to a mutation in Prs, which synthesizes the cor...

Stevens et al. describe the molecular basis for increased antibiotic tolerance in S. aureus COL: a prs mutation that reduces PRPP synthetase activity (leading to downregulation of pyrimidine, histidine, and tryptophan synthesis) plays a major role.
#MicroSky
onlinelibrary.wiley.com/doi/10.1111/...

The Mycobacterium tuberculosis Transposon Sequencing Database (MtbTnDB): A Large‐Scale Guide to Genetic Conditional Essentiality Mtb transposon sequencing database is a unified resource for exploring conditional gene essentiality in Mycobacterium tuberculosis. By standardizing over 150 transposon sequencing screens, it enables...

Jinich et al. present an important new resource for the Mtb community!
The Mycobacterium tuberculosis Transposon Sequencing Database (MtbTnDB) is an interactive web resource summarizing 150+ published screens.
#MicroSky #Mycobacterium #tuberculosis
onlinelibrary.wiley.com/doi/10.1111/...

Cyclic-di-AMP modulates cellular turgor in response to defects in bacterial cell wall synthesis - Nature Microbiology Brogan et al. uncover a signalling pathway in which levels of the nucleotide second messenger c-di-AMP increase in response to defects in cell wall synthesis. This regulatory pathway decreases turgor ...

Very happy to share that a large part of my thesis work is out today: B. subtilis uses the second messenger c-di-AMP to modulate its turgor pressure in response to the state of its cell envelope. www.nature.com/articles/s41...

Diagrams of Borrelia burgdorferi flagella, adapted from https://www.nature.com/articles/nrmicro1086

Regulation of the main structural element of Lyme spirochete flagella

"The Flagellin-specific chaperone FliS of Borrelia burgdorferi controls the cytoplasmic pool of Flagellins at the level of translation initiation, secretion, and proteolysis"
pubmed.ncbi.nlm.nih.gov/40491023/

#MicroSky

Time for Episode 95 of #MattersMicrobial! This time, Dr. Tory Hendry of Cornell University joins the #QualityQuorum to discuss aphids, symbiosis, and fluorescent bacteria. Please spread the #GoodMicrobialWord? microbe.tv

youtu.be/i9xoWApANNM?...

Bacterial sporulation (endospore formation) is complicated,but it turns out a lot of steps are regulated by classically defined developmental "checkpoints", and not events that are intrinsically required for the next step to occur. Zac Park reviews these in #Bacillus subtilis
doi.org/10.1146/annu...

Excited to share our latest review! Check it out to see what we know so far about how Staphylococcus aureus coordinates key processes during its cell cycle