#proteins

-- enzyme

-- topoisomerase class

-- subclass of type II topoisomerases

-- tetrameric

-- pronounced specificity to DNA substrates

-- SGS = strong gyrase binding sites

-- SGS is found in some phages and plasmids

-- target of many antibiotics -> nalidixic acid -> novobiocin -> ciprofloxacin

-- reduces topological strand during unwinding

-- ATP-dependent manner

-- allows bacteria to have free negative supercoils

-- moves in front of the progressing replication fork on DNA

-- causes negative supercoiling as it does

-- relaxes positive supercoils

-- loops the template to form a crossing, then cuts one of the double helices

-- changes the linking number by two

-- occurs in -> bacteria -> some parasites -> eukaryotic plastids -> some plant chloroplasts

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The Scientific Research Notes of S. Sunkavally. Years: 1986 - 1990.

The Scientific Research Notes of S. Sunkavally. Years: 1986 - 1990.

A study by researchers at Duke University School of Medicine identifies a new way that G protein–coupled receptors (GPCRs)—targets of roughly one-third of FDA-approved drugs—control signaling in cells. The paper is published in the journal Nature.

Imperfect polymer sequences still control protein function, revealing new design rules

What happens when a scientific problem seems too complex to solve precisely, yet understanding it could reshape how researchers design new materials and medicines? For decades, much of the polymer science community has relied on a "good enough" approach to a stubborn problem: binding a polymer to a protein in a precise way that reliably controls how the protein behaves. Polymers—long chains built from repeating small molecules called monomers—make up much of the material world, from plastic bags and clothing to advanced medicines. Designing those chains to interact with proteins, however, has pushed the limits of precision chemistry. In a study published in Angewandte Chemie, chemist Darwin Gomez, a member of Adrian Figg's lab, and fellow Virginia Tech researchers Ronnie Mondal and Swarnadeep Seth demonstrated that even when a polymer lacks a perfectly tailored sequence, the protein it binds to can still function as intended.

New recyclable protein textiles could cut microplastic pollution and lower clothing waste

The textile industry produces a substantial portion of the world's waste, with only about 12% of fiber materials ending up in recycling. Textiles also account for much of the microplastics in oceans. During every wash cycle, synthetic fibers shed microplastics that are flushed down the drain and eventually enter aquatic environments. Increasing textile recycling alone won't solve this problem because most petrochemical-based fibers are difficult to recycle and continue to release persistent microplastics throughout their life cycle. Engineers from Washington University in St. Louis may have a solution, thanks to dedicated synthetic biology work in the lab of Fuzhong Zhang, the Francis F. Ahmann Professor in the Department of Energy, Environmental & Chemical Engineering in the McKelvey School of Engineering and co-director of Synthetic Biology Manufacturing of Advanced Materials Research Center (SMARC).