Table 8.
Examples of differential genome display of Pyrococcus abyssi and Pyrococcus horikoshii using the COG approach
| Gene/COG Number | Phylogenetic pattern* | Function | Comment |
| Present in P.abyssi but not P. horikoshii | |||
| PAB2044/0547 | amt-szyqvdcebrhuj- - - - - -n- | Anthranilate phosphoribosyltransferase | The entire branched pathway for aromatic amino acid biosynthesis appears to be present in P. abyssi but not in P. horikoshii |
| PAB2045/0147 | amt-szyqvdcebrhuj- - - - - -n- | Anthranilate synthase component I | |
| PAB2046/0512 | amt-szyqvdcebrhuj- - - - - -n- | Anthranilate synthase component II | |
| PAB0307/0082 | - - - -szyqvdceb-huj- - - - -inx | DAHP synthase | |
| PAB2049/0159 | amt-szyqvdcebrhuj- - - - -in- | Tryptophan synthase α subunit | |
| PAB2048/0133 | amt-szyqvdcebrhuj- - - - -in- | Tryptophan synthase β subunit | |
| PAB0250/0031 | - - - -szyqvdcebrhuj- - - - - -n- | Cysteine synthase | P. abyssi appears to be the only euryarchaeon that encodes the typical cysteine biosynthesis pathway which it shares with A. pernix |
| PAB1595/2046 | a- - -szyq-dc-b- - -j- - - - - - - - | ATP sulfurylase | |
| PAB0781/0529 | a- - -szyq-dcebr- -j- - - - - -n- | Adenylylsulfate kinase | |
| PAB1839/0035 | - -t-szyqvdcebrh-jwgp-l-n- | Uracil phosphoribosyltransferase | |
| PAB2246/0827 | -m- -s- - - - - - -brhu-w-p- - - - - | Adenine-specific DNA methyltransferases | |
| PAB2154/0610 | amt-s- - - - - -e- -hujw-p- - -n- | Restriction enzymes type I helicase subunit | |
| Present in P. horikoshii but not P. abyssi | |||
| PH0369/0153 | - - -k- -y-v- -ebrh- - - - - -I--- | Galactokinase | |
| PH1048, PH1046/2309 | - - -k-z-q-d- -b- - - - - - -o- - - - | Leucyl aminopeptidase (aminopeptidase T) | |
| PH0365/1085 | a- -k- -y-v- -e-rh- - - - - - - - - - | Galactose-1-phosphate uridylyltransferase | |
| PH0896/1230 | - - -k- -yqvd-eb- - -j- - - - - -n- | Co/Zn/Cd efflux system component | |
| PH0162/1353 | amtk- - -qv- - - -r- - - - - - - - - - - | Predicted hydrolase of the HD superfamily | |
| PH1032/0338 | -m-k- - - - - -ce- -hu- - - - -I- - - | Site-specific DNA methylase dam | |
| PH0873/1401 | - -tk- - -q-dceb-uj- - - - - - - - | GTPase subunit (McrB) of a restriction endonuclease | |
*The designations are as in Table 6.