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John D. Helmann

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by John D. Helmann

johnhelmann.bsky.social
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...
The Fine Structure of the Gene on JSTOR
Seymour Benzer, The Fine Structure of the Gene, Scientific American, Vol. 206, No. 1 (January 1962), pp. 70-87
www.jstor.org
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Reposted by: John D. Helmann

evolvedbiofilm.bsky.social
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
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Reposted by: John D. Helmann

davidlalaouna.bsky.social
🚨 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...
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Reposted by: John D. Helmann

henrikstrahl.bsky.social
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...
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...
www.biorxiv.org
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Reposted by: John D. Helmann

evolvedbiofilm.bsky.social
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....
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...
www.embopress.org
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Reposted by: John D. Helmann

molmicrounihoh.bsky.social
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
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 ...
journals.asm.org
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Reposted by: John D. Helmann

redrockcity.bsky.social
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.
Elio Schaechter and Petra in San Diego
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Reposted by: John D. Helmann

romainstrock.bsky.social
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/...
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 ...
journals.plos.org
5 28 77

by John D. Helmann

johnhelmann.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).
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by John D. Helmann

johnhelmann.bsky.social
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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Reposted by: John D. Helmann

joergstuelke.bsky.social
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
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
academic.oup.com
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by John D. Helmann

johnhelmann.bsky.social
Thanks Christoph!
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by John D. Helmann

johnhelmann.bsky.social
Thanks Peter!

by John D. Helmann

johnhelmann.bsky.social
Thanks Betül! I hope your students find this helpful.

by John D. Helmann

johnhelmann.bsky.social
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
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,...
rdcu.be
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Reposted by: John D. Helmann

giedroclab.bsky.social
Our review on bacterial metallostasis is now online in Chemical Reviews! This collaboration by the Giedroc (@betainverse.bsky.social and @jsrocchio.bsky.social) and Capdevila labs delves into bacterial metal regulation. 🦠 #Microbiology #ChemicalReviews #BacterialMetallostasis doi.org/10.1021/acs....
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Reposted by: John D. Helmann

jbuttresssci.bsky.social
So happy our pre-print on daptomycin mechanism of action is now out! Here, we present three main findings: i) daptomycin does not form large membrane pores in either B. subtilis or S. aureus, (1/3)
biorxiv-microbiol.bsky.social
bioRxiv Microbiology @biorxiv-microbiol.bsky.social · Dec 21
The last resort antibiotic daptomycin exhibits two independent antibacterial mechanisms of action https://www.biorxiv.org/content/10.1101/2024.12.20.629673v1
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Reposted by: John D. Helmann

rcsbpdb.bsky.social
After a remarkable 300 columns, David Goodsell has retired from the Molecule of the Month. We are very grateful for his service.
@jiwasa.bsky.social will continue the series, beginning with January's article on Assembly Line Polyketide Synthases
Details: cdn.rcsb.org/rcsb-pd...
EDUCATION CORNER: Molecule of the Month: Celebrating  25 Years of Storytelling and Announcing New Beginnings
After a remarkable 300 columns, David Goodsell has retired from the Molecule of the Month series.  Janet Iwasa will be continuing the series for PDB-101.
cdn.rcsb.org
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Reposted by: John D. Helmann

kateduncan.bsky.social
ICYMI: some microbiology societies/organisations/journals @naturemicrobiol.bsky.social @microbiologysociety.org @asm.org @biorxiv-microbiol.bsky.social @embojournal.bsky.social @femsmicro.bsky.social @official-smbe.bsky.social @stcmicrobeblog.bsky.social @who.int @biologists.bsky.social #microsky
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Reposted by: John D. Helmann

biorxiv-microbiol.bsky.social
The role of lipoteichoic acid in Staphylococcus aureus cell wall integrity https://www.biorxiv.org/content/10.1101/2025.01.16.633316v1
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Reposted by: John D. Helmann

evolvedbiofilm.bsky.social
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...
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...
www.jbc.org
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Reposted by: John D. Helmann

veeninglab.com
Now published, congrats Bevika, Kinki, Vincent, Florian and Paddy! #MicroSky
www.nature.com/articles/s41...
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Reposted by: John D. Helmann, Mart Krupovìč

stcmicrobeblog.bsky.social
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
Figure 6. YjbH and the division machinery jointly act to confine phage components (A) OF237 (ftsA-gfp, yjbH-mCardinal) cells were infected with SPO1, placed on an agarose pad, and followed by time-lapse fluorescence microscopy. Shown are images from FtsA-GFP (green), YjbH-mCardinal (red), overlay (1) of FtsA-GFP and YjbH-mCardinal, and overlay (2) of FtsA-GFP, YjbH-mCardinal, and phase contrast (gray), captured at the indicated mpi. Arrows highlight FtsA rings (yellow), YjbH foci (white), and their proximity throughout time (blue). Scale bar, 1 μm. (B) An enlarged image corresponding to the bordered region in (A) (30 mpi, overlay [1]), with demarcated cell borders. Scale bar, 0.25 μm. An interpretive schematic illustrating YjbH (red) in proximity to FtsA (green) is depicted on the right.
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Reposted by: John D. Helmann

evolvedbiofilm.bsky.social
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/...
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by John D. Helmann

johnhelmann.bsky.social
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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Reposted by: John D. Helmann

evolvedbiofilm.bsky.social
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...
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...
www.nature.com
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Reposted by: John D. Helmann

molecularmicro.bsky.social
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...
onlinelibrary.wiley.com
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Reposted by: John D. Helmann

molmicrounihoh.bsky.social
👉 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
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...
onlinelibrary.wiley.com
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Reposted by: John D. Helmann

molecularmicro.bsky.social
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/...
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...
onlinelibrary.wiley.com
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Reposted by: John D. Helmann

molecularmicro.bsky.social
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/...
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...
onlinelibrary.wiley.com
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