AtTRB proteins are members of the SMH family defined by N-terminal Myb domain, central region with H1/5 domain and coiled-coil domain near C-terminus. SMH family is exclusively plant specific. Members of the SMH family are not only telomeric sequence binding due to their telobox-type Myb domain but they are also likely to regulate promotor sequences in various genes. So far we have characterized three SMH proteins. Although each of them is ds-telomeric repeat binding, some of them are also G-rich strand binding and they further differ in their ability to interact with other proteins, as was determined by the yeast two-hybrid system. The aim of this project is to find interaction partners of the SMH proteins directly in plant system via TAP-tag which allows two-step protein purification under native conditions. This project should also answer the question whether the AtTRB proteins are telomere localized or whether they distinguish interstitial telomeric repeats within promoter regions. The

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