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Characterization of a core fragment of the rhesus monkey TRIM5α protein.

Kar AK, Mao Y, Bird G, Walensky L, Sodroski J - BMC Biochem. (2011)

Bottom Line: This BCCL2 protein formed dimers and higher-order oligomers in solution.Approximately 40% of the BCCL2 secondary structure consisted of alpha helices.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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.

ABSTRACT

Background: 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.

Results: 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.

Conclusions: 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.

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Related in: MedlinePlus

Effect of zinc and dithiothreitol (DTT) on LLER oligomerization. The LLER protein was applied to a gel-filtration column in the presence of 25 μM ZnCl2 and the indicated concentrations of DTT and eluted at a flow rate of 0.3 ml/min. The profile of the eluted protein is shown.
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Figure 4: Effect of zinc and dithiothreitol (DTT) on LLER oligomerization. The LLER protein was applied to a gel-filtration column in the presence of 25 μM ZnCl2 and the indicated concentrations of DTT and eluted at a flow rate of 0.3 ml/min. The profile of the eluted protein is shown.

Mentions: Because the B-box 2 domain of the BCCL2 protein binds two zinc ions [16], we investigated the effect of zinc supplementation and DTT treatment on the expression and oligomerization of the LLER variant. No augmentation of LLER expression resulted from supplementation of growth medium with 25-100 mM ZnCl2; in fact, LLER expression was diminished at the highest ZnCl2 concentration tested (data not shown). The addition of ZnCl2 or DTT did not significantly affect the elution profile of the LLER protein on gel-filtration chromatography (Figure 4 and data not shown).


Characterization of a core fragment of the rhesus monkey TRIM5α protein.

Kar AK, Mao Y, Bird G, Walensky L, Sodroski J - BMC Biochem. (2011)

Effect of zinc and dithiothreitol (DTT) on LLER oligomerization. The LLER protein was applied to a gel-filtration column in the presence of 25 μM ZnCl2 and the indicated concentrations of DTT and eluted at a flow rate of 0.3 ml/min. The profile of the eluted protein is shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3025952&req=5

Figure 4: Effect of zinc and dithiothreitol (DTT) on LLER oligomerization. The LLER protein was applied to a gel-filtration column in the presence of 25 μM ZnCl2 and the indicated concentrations of DTT and eluted at a flow rate of 0.3 ml/min. The profile of the eluted protein is shown.
Mentions: Because the B-box 2 domain of the BCCL2 protein binds two zinc ions [16], we investigated the effect of zinc supplementation and DTT treatment on the expression and oligomerization of the LLER variant. No augmentation of LLER expression resulted from supplementation of growth medium with 25-100 mM ZnCl2; in fact, LLER expression was diminished at the highest ZnCl2 concentration tested (data not shown). The addition of ZnCl2 or DTT did not significantly affect the elution profile of the LLER protein on gel-filtration chromatography (Figure 4 and data not shown).

Bottom Line: This BCCL2 protein formed dimers and higher-order oligomers in solution.Approximately 40% of the BCCL2 secondary structure consisted of alpha helices.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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.

ABSTRACT

Background: 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.

Results: 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.

Conclusions: 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.

Show MeSH
Related in: MedlinePlus