[Genes of plant Ser/Thr protein phosphatases: detection of sequences related to PPT/rdgC]. / Geny Ser/Thr-fosfataz rasteni'i: detektsiia posledovatel'noste'i, rodstvennykh PPT/rdgC.

ABSTRACT

An unknown sequence that may encode a fragment of the Ser/Thr protein phosphatase (designated PP6Zm) related to PPT/rdgC phosphatases was identified using PCR on maize genomic DNA. A dbEST search using a partial amino acid sequence of PP6Zm revealed a putative homolog of PP6Zm expressed in Arabidopsis thaliana (EMBL AT6726). A search of the SwissProt database indicated that the partial amino acid sequence of AT6726 has the highest identity (54.3%) to the rdgC phosphatase from Drosophila melanogaster. The maize phosphatase PP1Zm6, described previously as a PP1 isoform (EMBO J., 1993, vol. 12, p. 3497), was found by us to be plant homolog of mammalian PPT. In addition, six fragments of new (pseudo) genes homologous to the phosphatase genes encoding PP1, PP2A, and PPX isoforms were detected in the maize genome. The existence in maize of a multigene PP2A family, reported only for dicotyledons, and of a PP1 multigene family, found earlier in both di- and monocotyledons, was shown.