Microbial rhodopsins are photoactive membrane proteins known for transporting small inorganic ions such as H+, Cl–, and Na+. Their compact structure─comprising seven transmembrane helices─has long been thought to limit their substrate range to such ions. Here, we report that several anion-pumping rhodopsins can also transport organic anions. In particular, a rhodopsin from cyanobacteria transports bulky organic anions, including those with a benzene ring, with volumes up to ∼120 Å3─five times larger than Cl–. These anions bind in the dark state and are translocated upon photoactivation, via a mechanism similar to Cl–. Notably, only anions with pKa values below 2 are transported, suggesting that negative charge is essential for binding. This study provides the first evidence that naturally occurring proteins can use light to transport organic compounds across membranes. These findings broaden the functional scope of microbial rhodopsins and open new possibilities for light-driven transport of organic ions.

Isoprenoid quinones constitute a class of redox lipids that are indispensable for electron transfer in a variety of cellular functions. For instance, plastoquinone, an integral component of plants, al...

The aquatic microbiome can influence cyanobacterial harmful algal blooms. Abundances of genes and transcripts for phosphorus acquisition, denitrification and nitrogen fixation were higher upstream, w....

UCYN-B drives high N2 fixation rates in previously unrecognized hot spots across the global ocean, making a significant contribution to the marine nitrogen

Fenoxaprop-p-ethyl is a widely employed aryloxyphenoxypropionate herbicide that inhibits acetyl-CoA carboxylase (ACCase), thus interfering with fatty acid biosynthesis in target organisms. While its ...

Cyanobacteria utilize a CO2-concentrating mechanism (CCM) to enhance photosynthetic efficiency by accumulating CO2 around RuBisCO, a process crucial f…

Cyanobacteria are ecologically pivotal microorganisms with immense biotechnological potential, particularly due to their capacity to synthesize fatty acids, terpenes, and other metabolites with applications ranging from biofuels to nutraceuticals. Despite this, many genera remain genomically underexplored. In this study, we present a polyphasic genomic analysis of two native strains, Aphanothece microscopica RSMan92 and A. stagnina RSMan2012, isolated from the Patos Lagoon estuary in Southern Brazil. Whole-genome sequencing and annotation enabled characterization of both genomes: RSMan92 spans 3.69 Mb in 701 contigs with 3,279 protein-coding sequences, while RSMan2012 comprises 3.28 Mb in 153 contigs with 3,567 protein-coding sequences. Phylogenetic analyses using MUSCLE and RAxML positioned these strains within a well-supported clade closely related to other Aphanothece RefSeq genome, highlighting their evolutionary relatedness and reinforcing the integrative taxonomic placement of the genus. Both strains reveal conserved gene repertoires associated with stress response, fatty acid biosynthesis, and secondary metabolite production (terpenes). Functional classification based on COG and KEGG annotations indicated strong representation of genes involved in lipid metabolism. To investigate how variations in temperature and light intensity modulate metabolite profiles, cultures were subjected to different environmental conditions. GC/EI-MS analysis revealed distinct patterns of fatty acid methyl ester production across conditions: both strains synthesized saturated and monounsaturated fatty acids, whereas only strain RSMan92 exhibited the capacity to synthesize polyunsaturated fatty acids, including linoleic acid derivatives, under variable cultivation conditions. This polyphasic genomic approach, providing novel genomic records, also reveals the fatty acid biosynthetic capacity and metabolic plasticity of Aphanothece strains, emphasizing their biotechnological relevance. Graphical abstract

The Fibroblast Growth Factor 2 (FGF2) is an important signaling protein that serves to activate a variety of biological processes in animal and human cells. The FGF2 comprises an uncommon β-barrel str...

Studies have shown that micro/nanoplastics (MNPs) are hazardous to many organisms. However, the underlying toxicity mechanism of MNPs, particularly th…

Multispecies biofilms combining Anabaena torulosa (An) with Trichoderma viride (Tr) along with either Providencia sp. (PW5) or Pseudomonas nitroreducens (B3) were optimized using eleven treatments wi....

1 Introduction Plastoquinone is the electron carrier in photosynthetic organisms, playing a crucial role in the photosynthetic electron transport chain. We p...

Biodegradation of toxic cyanobacterial cyclic peptides microcystins (MCs) by heterotrophic bacteria isolated from freshwater has gained global interest as an eco-friendly approach for water treatment....

Plants use photoperiod (i.e. day length) as a seasonal cue for timing when to flower. This ability, known as photoperiodism, also underlies phenomena such as migration, seasonal reproduction, and hib...

Accurate protein structure prediction followed by structural homology detection enable the functional annotation of otherwise obscure viral protein-co…

Abstract. Species are a fundamental unit of biodiversity. Yet, the existence of clear species boundaries among bacteria has long been a subject of debate.

This study compared the coagulation performance, floc characteristics, and algal cell integrity between cerium-based coagulants and polyaluminum chlor…

Cyanobacteria and green microalgae often co-exist during toxic algal blooms, but the influence of microcystins (MCs) on ionic homeostasis of these alg…

Prochlorococcus is the most numerically abundant photosynthetic organism in the oceans and plays a role in global carbon cycling. Despite its ecological significance and the availability of over a tho...

The frequency and extent of wildfire are increasing globally, and understanding the ecosystem impacts of fire can help guide management of burned area…