Members of this family adopt a coiled coil structure, with two antiparallel alpha-helices that are tightly strapped together by two disulfide bridges at each end. The protein sequence shows a cysteine motif, required for the stabilisation of the coiled-coil-like structure. Additional inter-helix hydrophobic contacts impart stability to this scaffold [3]. The precise function of this eukaryotic domain is, as yet, unknown [1]. MTCP1 is found in mitochondria. Mature-T-Cell Proliferation) is the first gene unequivocally identified in the group of uncommon leukemias with a mature phenotype [2].

1: Solution structure of human p8MTCP1, a cysteine-rich protein encoded by the MTCP1 oncogene, reveals a new alpha-helical assembly motif. Barthe P, Yang YS, Chiche L, Hoh F, Strub MP, Guignard L, Soulier J, Stern MH, van Tilbeurgh H, Lhoste JM, Roumestand C; J Mol Biol. 1997;274:801-815. PMID:9405159

2: MTCP-1: a novel gene on the human chromosome Xq28 translocated to the T cell receptor alpha/delta locus in mature T cell proliferations. Stern MH, Soulier J, Rosenzwajg M, Nakahara K, Canki-Klain N, Aurias A, Sigaux F, Kirsch IR; Oncogene. 1993;8:2475-2483. PMID:8361760

3: Synthesis and NMR solution structure of an alpha-helical hairpin stapled with two disulfide bridges. Barthe P, Rochette S, Vita C, Roumestand C; Protein Sci. 2000;9:942-955. PMID:10850804