General Comparative Features of thePyrococcus Genomes
| Genome features | P. abyssi | P. horikoshii | P. furiosus |
| Chromosome size (bp) | 1,765,118 | 1,738,505 | 1,908,253 |
| Protein coding regions | 91.1% | 91.2% | 92.5% |
| G+C content | 44.7% | 41.9% | 40.8% |
| Stable RNAs | |||
| tRNAs | 46 | 46 | 46 |
| tRNAs with introns | Trp, Met | Trp, Met | Trp, Met |
| Ribosomals | 16S-23S, | 16S-23S, | 16S-23S, |
| 5Sa, 5Sb | 5Sa, 5Sb, | 5Sa, 5Sb | |
| 7S | 7S | 7S | |
| Others | Rnase P | Rnase P | Rnase P |
| Open reading frames | 1,765 | 2061 | 2208 |
| Genes belonging to families of paralogs | 621 | 606 | 845 |
| Putative function assigned | 51% | 20% | — |
| Informational genes | 14% | — | — |
| Operational genes | 37% | — | — |
| Unknown function | 49% | 80% | — |
| Mobile elements | |||
| Inteins | 14 | 14 | 10 |
| Insertion Sequences | 1 vestigial IS | 1 vestigial IS | 24 |
| Repeats# | |||
| LCTR R1 family | 1 | 3 | 0 |
| LCTR R2 family | 3 | 3 | 7 |
[i] #LCTR are clusters of ∼30-bp-long tandem repeats separated by linkers ranging from 60 to 100 bp.
[ii] R1 family consensus: GTTTC-CGTAGAACNNANNAGTGTGGAAA
[iii] R2 family consensus: GTTNCANNAAGANNANAANAGAATTGAA