Stephen Waschuk et al. report that the fungus Leptosphaeria maculans possesses a rhodopsin protein able to translocate protons across membranes in response to light, a function thought to be unique to prokaryotes. Traditionally, respiration and chlorophyll-based photosynthesis are the two methods used by eukaryotes to create a proton gradient, whereas archaebacteria undergo retinal-based photos...

The origin of the eukaryotic genetic apparatus is thought to be central to understanding the evolution of the eukaryotic cell. Disagreement about the source of the relevant genes has spawned competing hypotheses for the origins of the eukaryote nuclear lineage. The iconic rooted 3-domains tree of life shows eukaryotes and archaebacteria as separate groups that share a common ancestor to the exc...

The genomic peculiarities among microbial eukaryotes challenge the conventional wisdom of genome evolution. Currently, many studies and textbooks explore principles of genome evolution from a limited number of eukaryotic lineages, focusing often on only a few representative species of plants, animals and fungi. Increasing emphasis on studies of genomes in microbial eukaryotes has and will conti...

Over the last years, antimicrobial peptides (AMPs) have been the focus of intense research toward the finding of a viable alternative to current antifungal drugs. Defensins are one of the major families of AMPs and the most represented among all eukaryotic groups, providing an important first line of host defense against pathogenic microorganisms. Several of these cysteine-stabilized peptides p...

Free-living microbial eukaryotes are an enigmatic group of organisms. Many have been discovered through traditional cultivation and microscopic observation, with continued observations leading to the acknowledgment that many small eukaryotic species are potentially dispersed at a global level (Finlay, 2002). While cell size could affect global distribution, habitat selection could allow for abu...

Sugar transporters in prokaryotes and eukaryotes belong to a large family of membrane proteins containing 12 transmembrane alpha-helices. They are divided into two classes: one facilitative (uniporters) and the other concentrative (cotransporters or symporters). The concentrative transporters are energised by either H+ or Na+ gradients, which are generated and maintained by ion pumps. The facil...

Members of the phylum Chlamydiae are obligate intracellular bacteria that were discovered about a century ago. Although Chlamydiae are major pathogens of humans and animals, they were long recognized only as a phylogenetically well-separated, small group of closely related microorganisms. The diversity of chlamydiae, their host range, and their occurrence in the environment had been largely und...