Alexandra Teslenko

Engineered reactivity of a bacterial E1-like enzyme enables ATP-driven modification of protein and peptide C termini Nature Chemistry - In living systems, ATP provides an energetic driving force for protein synthesis and modification. Now, an engineered enzymatic tool has been developed for high-yield, ATP-driven...

Excited to share our latest: we engineered the reactivity of a bacterial E1-like enzyme for ATP-driven modification of C termini. Our tool mimics the logic of peptide bond formation in biology for precision modification of proteins in vitro. 🧪https://rdcu.be/ewN7C

Zincore, an atypical coregulator, binds zinc finger transcription factors to control gene expression Zinc finger proteins (ZNFs) are the largest family of transcription factors, yet how they activate gene expression remains unclear. In this study, we identified Zincore, a protein complex consisting o...

In today’s publication in Science we introduce Zincore: a novel protein of QRICH1 and SEPHS1 and functions as a transcriptional coregulator dedicated to zinc finger transcription factors. Here’s how we found it: 🧵 www.science.org/doi/10.1126/... 1/11

CTCF binding landscape is shaped by the epigenetic state of the N-terminal nucleosome in relation to CTCF motif orientation Abstract. CTCF binding sites serve as anchors for the 3D chromatin architecture in vertebrates. The functionality of these anchors is influenced by the res

Excited to share our latest study published in Nucleic Acids Research: academic.oup.com/nar/article/...
It’s the cover story for Issue #12! We drew inspiration from Greek mythology to illustrate the endless work of CTCF in shaping the 3D genome architecture.

Intrinsically disordered regions facilitate Msn2 target search to drive promoter selectivity Transcription factors (TFs) regulate gene expression by binding specific DNA motifs, yet only a fraction of putative sites is occupied in vivo. Intrinsically disordered regions (IDRs) have emerged as ...

1/
New preprint!
How do transcription factors (TFs) use intrinsically disordered regions (IDRs) to find their target sites?

www.biorxiv.org/content/10.1...
#TranscriptionFactors #IDPs #SingleMolecule #Biophysics

Single-molecule analysis reveals the mechanism of chromatin ubiquitylation by variant PRC1 complexes Single-molecule experiments show that active conformation formation controls chromatin ubiquitylation kinetics by variant PRC1.

Our new study of chromatin ubiquitylation by variant PRC1 on the single-molecule scale: We visualize directly how vPRC1 ubiquitylates neighboring nucleosomes during a single binding event, showing a potential mechanism how H2Aub domains are established.
www.science.org/doi/10.1126/...

We are very grateful for the long-time financial support from the @erc.europa.eu, @snsf.ch, and EPFL (EDCH) who made this work possible! 🍀

Epigenetic landscape navigation by Polycomb complexes. Using a single-molecule approach, we provide mechanistic insight into how Polycomb enzymes interpret chromatin context to control gene expression. In our study, we reveal that vPRC1 dynamically engages chromatin to form a catalytically competent complex with E2 and ubiquitin, a process governed by subtype-specific activity.

Using single-molecule dynamics, we observe real-time vPRC1 ubiquitylation of the chromatin fibers. vPRC1 dynamically engages chromatin, a process depending on E2 and H2Aub, while its PCGF subunit governs the formation of the catalytically competent complex with E2~Ub and enzymatic processivity.

Single-molecule analysis reveals the mechanism of chromatin ubiquitylation by variant PRC1 complexes Single-molecule experiments show that active conformation formation controls chromatin ubiquitylation kinetics by variant PRC1.

If you always wanted to know the kinetics of how the Polycomb enzymes modify chromatin, we are thrilled to share our work!!! 🎉📄🧬🔬

Thank you, @beatfierz.bsky.social for all the guidance as well as the @lcbm-epfl.bsky.social group members for all the support!
doi.org/10.1126/scia...

A snapshot of the HLp tetramer (purple) wrapping ~60 bp of DNA (green).

Excited to share our new preprint on HLp—a bacterial histone from Leptospira perolatii that forms stable tetramers and wraps ~60 bp of DNA: "DNA Wrapping by a Tetrameric Bacterial Histone" www.biorxiv.org/content/10.1...

@mpi-bio-fml.bsky.social

There are days in life that shake you.

I’m shattered 💔 to share that I just found out that the US Government terminated my 2024 NIH Director’s Early Independence Award (~$2 million), threatening my long-promised assistant professor job at Columbia University
& academic career... 1/🧵

Graphic showing modification of mRNA with ADP-ribose mediated by bacterial enzyme cmdTAC

Check it out! Another novel RNA modification - ADP-ribosylation - that was previously only known on proteins. A cousin to #glycoRNA 👏

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

We made a photoswitchable HaloTag (psHaloTag), which can reversibly turn-on fluorogenic dyes upon illumination 💡. Congrats to Franzi, Bego and all co-authors, check out our preprint below 👇
www.biorxiv.org/content/10.1...

A screenshot of a paper on bioarxiv illustrating the lack of blue sky share button!

Would you like to see @biorxivpreprint.bsky.social add a share to blue sky button?! I know I would! Share this post to let @richardsever.bsky.social @erictopol.bsky.social and others at bioarxiv know!

🥳 Today we celebrated the PhD defense of our very first PhD student Kevin Schiefelbein 🤩 Kevin told us about his Lasso Peptide journey over the past four years, and it was so great to see the full story coming together. Congratulations Kevin, and thank you for everything! #proudPI

Stereochemistry in the disorder–order continuum of protein interactions - Nature Studies on protein–protein interactions using proteins containing d- or l-amino acids show that stereoselectivity of binding varies with the degree of disorder within the complex.

We did this crazy project where we tried to see if proteins could interact with their mirror image ligand. Seems impossible when proteins need to form 3D structures to interact. But what about if the interaction remains disordered???

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

behold our paper on Medusavirus nucleosomes. Fantastic work by Chelsea Toner, @nhoitsma.bsky.social, and Sashi Weerawarana This giant virus also encodes a linker histone, more about that in the paper 🧪👩‍🔬 🧵.
www.nature.com/articles/s41...

First attempt in a (loosely defined) Single-Molecule Biophysics starter pack. Please share and (self-) nominate. go.bsky.app/CteFZM5

Single-molecule analysis reveals the mechanism of chromatin ubiquitylation by variant PRC1 complexes https://www.biorxiv.org/content/10.1101/2024.10.25.620026v1 Chromatin regulation relies on "writer" enzymes that add post-translational modifications (PTMs) to

Single-molecule analysis reveals the mechanism of chromatin ubiquitylation by variant PRC1 complexes https://www.biorxiv.org/content/10.1101/2024.10.25.620026v1

Read–write mechanisms of H2A ubiquitination by Polycomb repressive complex 1 Nature - Cryo-electron microscopy and biochemical studies elucidate the read–write mechanisms of non-canonical PRC1-containing RYBP in histone H2A lysine 119 monoubiquitination and their...

Please see our paper in Nature on read-write mechanisms of H2AK119 ubiquitination by Polycomb repressive complex I. Congrats to the whole team, especially Victoria and huge thanks to our collaborator JP Armache! Also big thanks to Mark Foundation for Cancer Research for the support! rdcu.be/dZ5HZ

📯📯 Chemical Biology starter pack 📯📯
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Check out this list of ubiquitin and Ubl profiles to follow. Repost if you want me to add you to it. Let’s create a good community here ☁️ go.bsky.app/3VPQofn

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On November 20, the new class of peptide-cyanobenzene dye photocatalysts developed by Xingyu have been first made public in a preprint at ChemRxiv, including a great collaboration Wei Cai in the @beatfierz.bsky.social group and Dr. Anne Sophie Chauvin
chemrxiv.org/engage/chemr...