Molecular Cloning of Kunitz-Type Proteinase Inhibitor Group B Genes from Potato

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A. S. Speranskaya^1*, A. A. Krinitsina¹, P. Poltronieri², P. Fasano², A. Santino², A. B. Shevelev¹, and T. A. Valueva¹

¹Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33, 119071 Moscow, Russia; fax: (7-095) 954-2732; E-mail: annatar@aha.ru

²National Research Council of Italy, ISPA-CNR, Via Monteroni 14, Lecce, 73100, Italy; fax: +39(0)832420000

^* To whom correspondence should be addressed.

Received August 17, 2004; Revision received October 19, 2004

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Eighteen clones representing copies of four Kunitz-type proteinase inhibitor group B genes (PKPI-B) obtained by polymerase chain reaction cloning of potato (Solanum tuberosum L. cv. Istrinskii) genomic DNA were sequenced and analyzed. Three new genes were found and named PKPI-B1, PKPI-B2, and PKPI-B10: these were represented by five, two, and seven clones, respectively. The remaining four clones corresponded to the formerly characterized PKPI-B9 gene. These data show that at least four PKPI-B encoding genes are harbored in the genome of potato cv. Istrinskii. Their analysis suggests that variability of PKPI-B encoding genes in potato is limited and could be explained by cross-hybridization events in the ancestor forms rather than by random mutagenesis.

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KEY WORDS: Kunitz-type proteinase inhibitors, gene sequences, genome, potato

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