Journal
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
Volume 565, Issue -, Pages 25-31Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.abb.2014.11.005
Keywords
Intrinsically disordered protein; Heme binding; Small-angle X-ray scattering; Chemical modification; Conformation change
Categories
Funding
- JSPS [24570175, 23790320, 21249014, 24350081]
- Grants-in-Aid for Scientific Research [25109504, 21249014, 24120001, 24570175, 23790320] Funding Source: KAKEN
Ask authors/readers for more resources
The transcriptional repressor Bach2 regulates humoral and cellular immunity, including antibody class switching. It possesses a basic leucine zipper domain that mediates DNA binding. Heme inhibits the DNA-binding activity of Bach2 in vitro and induces the degradation of Bach2 in B cells. However, the structural basis of the heme-Bach2 interaction has not been identified. Spectroscopic analyses revealed that Bach2(331-52) is the heme-binding domain, as it includes three Cys-Pro motifs known to be important for heme binding. Heme-titration experiments demonstrated the presence of 5- and 6-coordinated heme-binding modes. Circular dichroism measurements indicated that Bach2(331-52) exists mostly in a random-coil conformation. However, dynamic light scattering analyses showed that, upon heme binding to Bach2331-520, this region becomes denatured at a lower temperature, as compared with unbound Bach2(331-520). In addition, small-angle X-ray scattering and chemical modification analyses revealed that heme binding induces conformational alterations within the unstructured region. A GAL4-based luciferase assay in 293T cells showed that heme alters the protein interactions mediated by Bach2(331-520). These observations suggested that the unstructured region of Bach2 is important for heme binding, and consequently for its functional regulation. (C) 2014 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available