Cloning a sequence, coding an SKT1 family protease inhibitor from potato

Seven structurally similar clones from potato (Solanum tuberosum L.), cv. Istrinskii genomic DNA were isolated by cloning of the PCR products. It was suggested that five of these clones were the amplified copies of the same gene. Based on comparative and structural analysis of these clones, initial nucleotide structure of the gene was reconstructed. It appeared to be highly homologous (98%) to the already published sequences encoding the proteins belonging to the soybean Kunitz trypsin inhibitor family (SKTI). Comparison of the results with the previously published data on the SKTI-type proteinase inhibitors from potato of cv. Istrinskii suggests that the gene examined encodes both chains of the earlier described PSPI-21-6.3 protein [9].