Background and significance
In Heidelberg, a critical mass of research groups investigates processes and molecular machineries in eukaryotes that guide genes from transcription to translation. These researchers will now combine in-depth studies of individual complexes and processes - using structural, biochemical, biophysical and bio-computational methods - with systemic approaches that place them into the context of global networks and eukaryotic evolution.

Three developments during the first phase of CellNetworks were essential for this collaborative research topic: (i) the genome sequence of C. thermophilum, (ii) the Consortium for Structural Biology in Heidelberg (ConStruct.HD), and (iii) development of technology platforms (e.g. cryo electron microscopy, Schröder; crystallization platform, Sinning; bioinformatics, Russell and Bork).

Chaetomium thermophilum: an eukaryotic model organism for biochemical and structural analysis: In the past, thermophilic prokaryotes have been crucial to unravel the molecular mechanisms of conserved key protein complexes and entire macromolecular assemblies. However, many eukaryotic proteins are not present in prokaryotes and the utilization of thermophilic homologues to study the structure and function of conserved eukaryotic molecular machines was therefore not possible. Among the eukaryotic organisms, only a few microorganisms grow at temperatures above 50°C.

Amongst these is C. thermophilum, whose genome was sequenced and annotated by Hurt and Bork. The C. thermophilum genome consists of 28,178,400 base pairs and about 7,200 open reading frames. As described above, proteins of this filamentous fungus exhibit extraordinary thermostability and protease resistance and have proven ideal for crystallization.