Table 1. Unclassified encoded by Polintons

Protein Polintons Length, Similar Description aa GenBank Family Species proteins*

Polinton-1_DR Fish 280 Polinton-2_DR Fish 282 Polinton-1_XT Frog 248 Polinton-2_XT Frog 247 Polinton-1_SPU Lizard - Polinton-1_CI Sea squirt 249 A profile derived from the PX multiple alignment PX Polinton-2_CI Sea squirt 248 — does not match (based on PSI-BLAST) any proteins Polinton-1_SP Sea urchin 252 that are not encoded by Polintons. Polinton-2_SP Sea urchin 255 Polinton-3_SP Sea urchin 253 Polinton-5_SP Sea urchin 255 Polinton-1_TC Beatle 291 Polinton-1_DY Fruit fly 182

Polinton-1_DR Fish 435 Polinton-2_DR Fish 435 Polinton-1_XT Frog 436 Polinton-2_XT Frog 435 Polinton-1_SPU Lizard 435 This is the most conserved one among the Polinton-1_CI Sea squirt 431 Polinton-encoded unclassified proteins. Its Polinton-2_CI Sea squirt 428 conservation is comparable to that of POLB and PY Polinton-1_SP Sea urchin 442 — INT. Polinton-2_SP Sea urchin 442 A profile derived from the PX multiple alignment Polinton-3_SP Sea urchin 444 does not match any proteins that are not encoded by Polinton-4_SP Sea urchin 444 Polintons. Polinton-5_SP Sea urchin 444 Polinton-1_TC Beatle 437 Polinton-1_DY Fruit fly 430 Polinton-1_CB Nematode 287

Polinton-1_DR Fish 151 Polinton-2_DR Fish 156 Polinton-1_XT Frog 146 Polinton-2_XT Frog 147 Polinton-1_CI Sea squirt 141 Polinton-2_CI Sea squirt 140 A profile derived from the PX multiple alignment PW Polinton-1_SP Sea urchin 121 — does not match any proteins that are not encoded by Polinton-2_SP Sea urchin 120 Polintons. Polinton-3_SP Sea urchin 160 Polinton-4_SP Sea urchin 146 Polinton-5_SP Sea urchin 153 Polinton-1_TC Beatle 144 Polinton-1_DY Fruit fly 156

Polinton-1_DR Fish 256 Polinton-2_DR Fish 260 Polinton-1_XT Frog 254 Polinton-2_XT Frog 209 Polinton-1_SPU Lizard 232 Polinton-1_CI Sea squirt 223 A profile derived from the PX multiple alignment PZ Polinton-2_CI Sea squirt 207 — does not match any proteins that are not encoded by Polinton-1_SP Sea urchin 250 Polintons. Polinton-2_SP Sea urchin 253 Polinton-3_SP Sea urchin 246 Polinton-4_SP Sea urchin 259 Polinton-5_SP Sea urchin 238 Polinton-1_TC Beatle 257 PC1 Polinton-1_CB Nematode 830 —— PC2 Polinton-1_CB Nematode 352 — — PTV1 Polinton-1_TV Protist 316 — Coiled-coil-like protein Protein Polintons Length, Similar Description aa GenBank Family Species proteins* Matches glycoproteins/structural proteins from NP_899594 phages, including short tail fibers, responsible for PTV2 Polinton-1_TV Protist 543 (E = 0.002) adsorption to host cells and interaction with receptors. PTV3 Polinton-1_TV Protist 236 — — PTV4 Polinton-1_TV Protist 232 — — PTV5 Polinton-1_TV Protist 247 — — It is similar (E = 10–21) to several hypothetical Polinton-1_TV Protist 546 PTV6 — proteins annotated in Entamoeba histolytica. These Polinton-1_EI Protist 508 proteins are encoded by Polintons. It is similar to a protein encoded by the B263R NP_042780 PGI1 Polinton-1_GI Fungus 263 in African swine fever . Function of this protein (E = 10–18) is unknown. Its N-terminal portion (positions 50–210) is distantly similar (E = 0.05) to numerous kinesin and myosin proteins. Its C-terminal portion (pos. 605- PGI2 Polinton-1_GI Fungus 972 — 972) is distantly similar (E = 0.1) to Gypsy/Ty3 gag- like proteins. Therefore, this protein can be encoded by some Gypsy LTR inserted in Polinton. This protein can be an ATPase. It contains a Walker PPI1 Polinton-1_PI Fungus 615 — 1 motif (positions 220–230).

*GenBank accession nos. of proteins that are best matches and not encoded by Polintons (corresponding BLASTP E values are shown in parentheses).