Characterization of a core fragment of the rhesus monkey TRIM5α protein

• Published in: BMC biochemistry 2011-01, Vol.12 (1), p.1-1, Article 1
• Main Authors: Kar, Alak K, Mao, Youdong, Bird, Gregory, Walensky, Loren, Sodroski, Joseph
• Format: Article
• Language: English
• Subjects: Animals; Dimerization; Escherichia coli; Macaca mulatta; Models, Molecular; Multiprotein Complexes - genetics; Multiprotein Complexes - metabolism; Protein Interaction Domains and Motifs; Protein Structure, Secondary - genetics; Proteins - chemistry; Proteins - genetics; Proteins - isolation & purification; Proteins - metabolism; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - isolation & purification; Recombinant Fusion Proteins - metabolism; Temperature; Zinc - metabolism
• ISSN: 1471-2091; 1471-2091
• DOI: 10.1186/1471-2091-12-1

Like all tripartite motif (TRIM) proteins, the retroviral restriction factor TRIM5α consists of RING, B-box 2 and coiled-coil domains, with a C-terminal B30.2(SPRY) domain. Although structures have been determined for some individual TRIM domains, the structure of an intact TRIM protein is unknown. Here, we express and characterize a protease-resistant 29-kD core fragment containing the B-box 2, coiled coil and adjacent linker (L2) region of TRIM5α. This BCCL2 protein formed dimers and higher-order oligomers in solution. Approximately 40% of the BCCL2 secondary structure consisted of alpha helices. Partial loss of alpha-helical content and dissociation of dimers occurred at 42°C, with the residual alpha helices remaining stable up to 80°C. These results indicate that the B-box 2, coiled-coil and linker 2 regions of TRIM5α form a core dimerization motif that exhibits a high level of alpha-helical content.