Identification of psi3Tom20, a novel processed pseudogene of the human Tom20 gene, and complete characterization of psi1Tom20 and psi2Tom20.

We report the identification and characterization of psi3Tom20, a novel processed pseudogene of the human Tom20 (hTom20) gene, which is 96.2% similarity with the hTom20 cDNA and is 5' and 3' truncated. In addition, we present the complete characterization of psi2Tom20 and psi2Tom20, the two other recently reported members of this pseudogene family. Comparison of the sequences of psi3Tom20 with that of the previously reported psi2Tom20 revealed and corrected an error in the previously determined sequence of psi2Tom20. A detailed analysis of these three pseudogenes, including their flanking regions, is presented. It suggests they probably arose from mRNAs that were polyadenylated at different sites. Possible mechanisms involved in their integration as retroposons are also discussed.