Proteins operate through a few critical residues, yet most proteins remain uncharacterized at the deep molecular resolution, particularly within essential genes, where functional dissection is obstructed by lethality. Here, we establish a platform for mutational scanning of essential genes at their endogenous locus, combining a repressible complementation system with multiplexed CRISPR-based genome editing in budding yeast. Our approach provides a generalizable framework for dissecting essential protein function in vivo, expanding the capacity to map critical residues underlying essential cellular processes. We applied this strategy to NRD1, encoding an essential RNA Polymerase II (RNAPII) termination factor and performed a systematic alanine scanning with near-saturation coverage. We discovered novel and unexpected lethal mutations in the CTD-interacting domain (CID), thus revealing an unanticipated importance for this domain. Overall, our results demonstrate the power of our mutation scanning platform to map critical residues underlying essential cellular processes. ### Competing Interest Statement The authors have declared no competing interest. European Molecular Biology Organization, https://ror.org/04wfr2810, ALTF 889-2022

Environmental stress reduces species growth rates, but its impact on the function of microbial communities is less clear. Here, we experimentally demonstrate that increasing salinity stress shifts com...

Easy wrangling and model-free analysis of microbial growth curve data, as commonly output by plate readers. Tools for reshaping common plate reader outputs into tidy formats and merging them with desi...

Bacteria evolving within humans employ strategies to overcome trade-offs. Here, the authors report that the cystic fibrosis-associated pathogen Burkholderia dolosa alternates phenotypes in vivo by acc...

Nature - Non-antibiotic drugs from a wide range of therapeutic classes can alter the ability of gut commensals to resist invasion by enteropathogens, a previously underappreciated side effect of...

Experimental perturbation of soil pH leads to a generalizable model of the soil microcosm comprising three functional regimes with distinct mechanisms linking environmental change to metabolite dynami...

Zip promotes the accumulation of free phages in bacterial lysogen communities, safeguarding phage progeny.

The bacterium Listeria monocytogenes can be pathogenic to humans and cause listeriosis, a potentially fatal infection. Until now, the variability in the pathogenicity of Listeria monocytogenes was not...

Artificial intelligence (AI) promises to accelerate scientific discovery, but it remains unclear whether AI systems can perform fully autonomous research, and whether they can do so while adhering ...

Resistance to one antibiotic can make bacteria resistant or sensitive to another antibiotic, opening paths for combinatorial treatments. This study presents an approach to systematically discover and ...

Differences in virulence across the Listeria monocytogenes species are determined by the fine-tuning of SigB pathway responsiveness and reflect host adaptation.

YouTube video by Lukas Hafner