Bilaud T, Koering C E, Binet-Brasselet E, Ancelin K, Pollice A, Gasser S M, Gilson E
Laboratoire de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Ecole Normale Supérieure de Lyon, France.
Nucleic Acids Res. 1996 Apr 1;24(7):1294-303. doi: 10.1093/nar/24.7.1294.
The yeast TTAGGG binding factor 1 (Tbf1) was identified and cloned through its ability to interact with vertebrate telomeric repeats in vitro. We show here that a sequence of 60 amino acids located in its C-terminus is critical for DNA binding. This sequence exhibits homologies with Myb repeats and is conserved among five proteins from plants, two of which are known to bind telomeric-related sequences, and two proteins from human, including the telomeric repeat binding factor (TRF) and the predicted C-terminal polypeptide, called orf2, from a yet unknown protein. We demonstrate that the 111 C-terminal residues of TRF and the 64 orf2 residues are able to bind the human telomeric repeats specifically. We propose to call the particular Myb-related motif found in these proteins the 'telobox'. Antibodies directed against the Tbf1 telobox detect two proteins in nuclear and mitotic chromosome extracts from human cell lines. Moreover, both proteins bind specifically to telomeric repeats in vitro. TRF is likely to correspond to one of them. Based on their high affinity for the telomeric repeat, we predict that TRF and orf2 play an important role at human telomeres.
酵母端粒结合因子1（Tbf1）是通过其在体外与脊椎动物端粒重复序列相互作用的能力而被鉴定和克隆的。我们在此表明，位于其C端的一段60个氨基酸的序列对于DNA结合至关重要。该序列与Myb重复序列具有同源性，并且在来自植物的五种蛋白质中保守，其中两种已知可结合端粒相关序列，以及来自人类的两种蛋白质，包括端粒重复结合因子（TRF）和来自一种未知蛋白质的预测C端多肽orf2。我们证明TRF的111个C端残基和64个orf2残基能够特异性结合人类端粒重复序列。我们建议将在这些蛋白质中发现的特定Myb相关基序称为“端粒盒”。针对Tbf1端粒盒的抗体在人类细胞系的核提取物和有丝分裂染色体提取物中检测到两种蛋白质。此外，这两种蛋白质在体外均特异性结合端粒重复序列。TRF可能对应其中之一。基于它们对端粒重复序列的高亲和力，我们预测TRF和orf2在人类端粒中起重要作用。
