Deep investigation of the tetracycline destructase sequence-structure-function landscape identifies new enzymes, and provide fundamental insights into their antibiotic-inactivating function.

Bacteria pack their genomes much in the same way Bingham packs for his flights: all the essentials in one bag. For most species, the genome is one circular chromosome that encodes all the essential genes needed to survive. Though a measly 2% of the human genome actually codes for proteins (the remaining 98% being cluttered with so-called “junk DNA”) bacterial chromosomes are packed to the brim with protein-coding genes, with an average protein-coding density of 87%.

Outstanding scientists are frequently recognized with species named in their honor (eponyms). Charles Darwin has over 300 taxa named after him, using several latinizations such as darwini, darwinianus, darwinianum, darwiniana, and darwinensis. However, this practice of professional recognition — like many in the sciences — is fraught with gender bias. In a recent report published in the International Journal of Systematic and Evolutionary Microbiology, Freese and colleagues examined the names of Bacteria and Archaea (i.e. prokaryotes) which honor people. They found that just 14.8% (299/2018) of prokaryotes named after people were named after women

The image is iconic: A lineup of six figures. At the rear is a chimpanzee-like figure — short, hairy, with a pronounced muzzle, and hunched-over on all fours. The next looks similar but is more upright and walks on two legs. The trend continues, with each successive figure becoming a little taller, a little less hunched, with less body hair and a smaller jaw. Until at the front of the line you reach Homo sapiens. Hairless, fully upright, with close-cropped hair and a neatly trimmed beard, “Modern Man” boldly strides into the future. Instantly recognizable and universally understood to depict the evolution of man, this is one of the most famous scientific illustrations of all time. It is also wrong.

While much is known about how proteins self-assemble in water—changing from a string of polypeptides into a folded, functional shape—relatively little is known about how this is done in the cell membrane. Dr. Janice Robertson, Assistant Professor of Biochemistry and Molecular Biophysics, and her lab use single-molecule techniques and computational modeling to find answers to the questions surrounding membrane protein assembly.

Microbiologists have long thought that extra­cel­lu­lar electron transfer (EET) – the process of trans­fer­ring electrons from the cytosol to the exterior of the cell – was limited to exotic, mineral-respiring, Gram-negative bac­te­ria. However, new findings from the Portnoy Lab (Light et al., 2018) suggests that EET is much more common than previously thought. By way of a novel flavin-based mechanism, a diverse group of non-mineral re­spiring, Gram-positive bacteria have also been found to engage in EET.

Scientists have long puzzled over why bacteria contain so many “redundant” enzymes. Why make several molecules that do the same job, interchangeably, when it would be much more efficient to make just one? New research from Washington University in St. Louis suggests that many of these so-called redundant enzymes are actually specialists that ensure maximal growth across different environments.

On November 25, news broke that a Chinese scientist, Dr. He Jiankui, had allegedly produced the first CRISPR-edited babies, twin girls named Lulu and Nana. This set off a firestorm within the international scientific community. He has been accused of violating numerous scientific conventions, ethical safeguards, and the global consensus on human germline gene modification. The scandal has been described as “the worst possible scenario for introducing the first gene-edited babies.”