The use of thermostable fluorescent proteins for live imaging in .

Introduction: Among hyperthermophilic organisms, protein localization is challenging due to the high growth temperatures that can disrupt proper folding and function of mostly mesophilic-derived fluorescent proteins. While protein localization in the thermophilic model archaeon has been achieved using antibodies with fluorescent probes in fixed cells, the use of thermostable fluorescent proteins for live imaging in thermophilic archaea has so far been unsuccessful. Given the significance of live protein localization in the field of archaeal cell biology, we aimed to identify fluorescent proteins for use in .

Proteins containing photosynthetic reaction centre domains modulate FtsZ-based archaeal cell division.

Cell division in all domains of life requires the orchestration of many proteins, but in Archaea most of the machinery remains poorly characterized. Here we investigate the FtsZ-based cell division mechanism in Haloferax volcanii and find proteins containing photosynthetic reaction centre (PRC) barrel domains that play an essential role in archaeal cell division. We rename these proteins cell division protein B 1 (CdpB1) and CdpB2.

Archaeal GPN-loop GTPases involve a lock-switch-rock mechanism for GTP hydrolysis.

GPN-loop GTPases have been found to be crucial for eukaryotic RNA polymerase II assembly and nuclear trafficking. Despite their ubiquitous occurrence in eukaryotes and archaea, the mechanism by which these GTPases mediate their function is unknown. Our study on an archaeal representative from showed that these dimeric GTPases undergo large-scale conformational changes upon GTP hydrolysis, which can be summarized as a lock-switch-rock mechanism.

Putative nucleotide-based second messengers in archaea.

Second messengers transfer signals from changing intra- and extracellular conditions to a cellular response. Over the last few decades, several nucleotide-based second messengers have been identified and characterized in especially bacteria and eukaryotes. Also in archaea, several nucleotide-based second messengers have been identified.

The missing enzymatic link in syntrophic methane formation from fatty acids.

The microbial production of methane from organic matter is an essential process in the global carbon cycle and an important source of renewable energy. It involves the syntrophic interaction between methanogenic archaea and bacteria that convert primary fermentation products such as fatty acids to the methanogenic substrates acetate, H, CO, or formate. While the concept of syntrophic methane formation was developed half a century ago, the highly endergonic reduction of CO to methane by electrons derived from β-oxidation of saturated fatty acids has remained hypothetical.