The Asgard archaeal origins of Arf family GTPases involved in eukaryotic organelle dynamics.

The evolution of eukaryotes is a fundamental event in the history of life. The closest prokaryotic lineage to eukaryotes, the Asgardarchaeota, encode proteins previously found only in eukaryotes, providing insight into their archaeal ancestor. Eukaryotic cells are characterized by endomembrane organelles, and the Arf family GTPases regulate organelle dynamics by recruiting effector proteins to membranes upon activation.

Communication between DNA polymerases and Replication Protein A within the archaeal replisome.

Replication Protein A (RPA) plays a pivotal role in DNA replication by coating and protecting exposed single-stranded DNA, and acting as a molecular hub that recruits additional replication factors. We demonstrate that archaeal RPA hosts a winged-helix domain (WH) that interacts with two key actors of the replisome: the DNA primase (PriSL) and the replicative DNA polymerase (PolD). Using an integrative structural biology approach, combining nuclear magnetic resonance, X-ray crystallography and cryo-electron microscopy, we unveil how RPA interacts with PriSL and PolD through two distinct surfaces of the WH domain: an evolutionarily conserved interface and a novel binding site.

Domain architecture of the MabR (), a member of the PucR transcription factor family.

MabR (), a PucR-type transcription factor, plays a crucial role in regulating mycolic acid biosynthesis in . To understand its regulatory mechanisms, we determined the crystal structures of its N-terminal and C-terminal domains. The N-terminal domain adopts a globin-like fold, while the C-terminal domain comprises an α/β GGDEF domain and an all-α effector domain with a helix-turn-helix DNA-binding motif.

Dietary pentadecanoic acid supplementation at weaning in essential fatty acid-deficient rats shed light on the new family of odd-chain n-8 PUFAs.

Pentadecanoic acid (C15:0) is a saturated odd-chain fatty acid (OCFA), mainly found in dairy products. Its physiological and nutritional effects are still unknown, yet some recent evidences suggest it might be beneficial to human health. Moreover, pentadecanoic acid has recently been suspected of having essential roles in humans, although the mechanisms are not described.

Use of stable isotope-labeled fatty acids to measure desaturase activities with negative chemical ionization GC-MS.

Fatty acid desaturases are key enzymes in lipid metabolism. They introduce double bonds between defined carbons of the fatty acyl chain and catalyze rate-limiting steps in the biosynthesis of polyunsaturated fatty acids. For decades, in vitro desaturase activities have been determined by using radiolabeled fatty acids as substrates, incubated with tissue or cell fractions containing membrane-bound desaturases.