The article provides a comprehensive overview of the complete genome sequence of the hyperthermophilic, sulphate-reducing archaeon *Archaeoglobus fulgidus*. The genome consists of a single, circular chromosome of 2,178,400 base pairs with an average G+C content of 48.5%. The study identifies 2,436 open reading frames (ORFs), with an average size of 822 bp, and highlights extensive correlation between information processing systems and biosynthetic pathways with those in the archaeon *Methanococcus jannaschii*. Key findings include: 1. **Genome Structure**: The genome contains regions with low G+C content rich in genes for lipopolysaccharide biosynthesis and high G+C content regions with genes for large ribosomal RNAs, proteins involved in haem biosynthesis, and transporters. 2. **Gene Duplication**: A. fulgidus exhibits extensive gene duplication, particularly in pathways for carbon utilization and biosynthesis, suggesting significant metabolic differentiation. 3. **Biosynthetic Pathways**: The biosynthetic pathways for essential components such as amino acids, cofactors, and purines are highly conserved with *M. jannaschii*, while central intermediary metabolism shows less overlap. 4. **Regulatory Networks**: A. fulgidus has complex sensory and regulatory networks, including over 55 proteins with presumed regulatory functions and multiple signal-transducing histidine kinases. 5. **Replication, Repair, and Cell Division**: The cell division machinery is similar to that of *M. jannaschii*, but lacks certain cdc genes found in *M. jannaschii*. 6. **Transcription and Translation**: A. fulgidus has distinct transcriptional and translational systems from both prokaryotes and eukaryotes, with simplified initiation mechanisms and unique tRNA maturation enzymes. 7. **Biosynthesis of Essential Components**: The archaeon can synthesize many essential compounds, including amino acids, cofactors, and purines, with some pathways resembling those of *Bacillus subtilis* more than *Escherichia coli*. 8. **Cell Membrane**: A. fulgidus has a unique cell membrane composed of ether lipids with a glycerophosphate backbone, which is obtained through multiple biosynthetic pathways. The study concludes that the genome sequence provides new insights into how A. fulgidus exploits its environment, particularly in sulfur oxide reduction and carbon utilization, and highlights the importance of gene duplication in increasing physiological diversity.The article provides a comprehensive overview of the complete genome sequence of the hyperthermophilic, sulphate-reducing archaeon *Archaeoglobus fulgidus*. The genome consists of a single, circular chromosome of 2,178,400 base pairs with an average G+C content of 48.5%. The study identifies 2,436 open reading frames (ORFs), with an average size of 822 bp, and highlights extensive correlation between information processing systems and biosynthetic pathways with those in the archaeon *Methanococcus jannaschii*. Key findings include: 1. **Genome Structure**: The genome contains regions with low G+C content rich in genes for lipopolysaccharide biosynthesis and high G+C content regions with genes for large ribosomal RNAs, proteins involved in haem biosynthesis, and transporters. 2. **Gene Duplication**: A. fulgidus exhibits extensive gene duplication, particularly in pathways for carbon utilization and biosynthesis, suggesting significant metabolic differentiation. 3. **Biosynthetic Pathways**: The biosynthetic pathways for essential components such as amino acids, cofactors, and purines are highly conserved with *M. jannaschii*, while central intermediary metabolism shows less overlap. 4. **Regulatory Networks**: A. fulgidus has complex sensory and regulatory networks, including over 55 proteins with presumed regulatory functions and multiple signal-transducing histidine kinases. 5. **Replication, Repair, and Cell Division**: The cell division machinery is similar to that of *M. jannaschii*, but lacks certain cdc genes found in *M. jannaschii*. 6. **Transcription and Translation**: A. fulgidus has distinct transcriptional and translational systems from both prokaryotes and eukaryotes, with simplified initiation mechanisms and unique tRNA maturation enzymes. 7. **Biosynthesis of Essential Components**: The archaeon can synthesize many essential compounds, including amino acids, cofactors, and purines, with some pathways resembling those of *Bacillus subtilis* more than *Escherichia coli*. 8. **Cell Membrane**: A. fulgidus has a unique cell membrane composed of ether lipids with a glycerophosphate backbone, which is obtained through multiple biosynthetic pathways. The study concludes that the genome sequence provides new insights into how A. fulgidus exploits its environment, particularly in sulfur oxide reduction and carbon utilization, and highlights the importance of gene duplication in increasing physiological diversity.