HMG-box
{{Short description|Protein domain which is involved in DNA binding}}
{{Infobox protein family
| Symbol = PF00505
| Name = HMG (high mobility group) box
| image = 2LEF.png
| width = 300px
| caption = NMR structure of the HMG-box domain of the LEF1 protein (rainbow colored, N-terminus = blue, C-terminus = red) complexed with DNA (brown) based on the {{PDB|2LEF}} coordinates.
| Pfam = PF00505
| Pfam_clan = CL0114
| ECOD = 190.1.1
| InterPro = IPR009071
| SMART=
| PROSITE=
| SCOP = 1hsm
| TCDB =
| OPM family =
| OPM protein =
| PDB = {{PDB2|1aab}}, {{PDB2|1cg7}}, {{PDB2|1ckt}}, {{PDB2|1e7j}}, {{PDB2|1gt0}}, {{PDB2|1hme}}, {{PDB2|1hmf}}, {{PDB2|1hry}}, {{PDB2|1hrz}}, {{PDB2|1hsm}}, {{PDB2|1hsn}}, {{PDB2|1i11}}, {{PDB2|1j3x}}, {{PDB2|1j46}}, {{PDB2|1j47}}, {{PDB2|1j5n}}, {{PDB2|1k99}}, {{PDB2|1lwm}}, {{PDB2|1nhm}}, {{PDB2|1nhn}}, {{PDB2|1o4x}}, {{PDB2|1qrv}}, {{PDB2|1s9m}}, {{PDB2|1sx9}}, {{PDB2|1v64}}, {{PDB2|1wgf}}, {{PDB2|1wxl}}, {{PDB2|2crj}}, {{PDB2|2cs1}}, {{PDB2|2lef}}
}}
In molecular biology, the HMG-box (high mobility group box) is a protein domain which is involved in DNA binding.{{cite journal |vauthors=Stros M, Launholt D, Grasser KD | title = The HMG-box: a versatile protein domain occurring in a wide variety of DNA-binding proteins | journal = Cell. Mol. Life Sci. | volume = 64 | issue = 19–20 | pages = 2590–606 |date=October 2007 | pmid = 17599239 | doi = 10.1007/s00018-007-7162-3 | s2cid = 28156847 | pmc = 11136187 }} The domain is composed of approximately 75 amino acid residues that collectively mediate the DNA-binding of chromatin-associated high-mobility group proteins. HMG-boxes are present in many transcription factors and chromatin-remodeling complexes, where they can mediate non-sequence or sequence-specific DNA binding.{{cite journal |last1=Štros |first1=M. |last2=Launholt |first2=D. |last3=Grasser |first3=K. D. |title=The HMG-box: a versatile protein domain occurring in a wide variety of DNA-binding proteins |journal=Cellular and Molecular Life Sciences |date=October 2007 |volume=64 |issue=19–20 |pages=2590–2606 |doi=10.1007/s00018-007-7162-3 |pmid=17599239 |url=https://link.springer.com/article/10.1007/s00018-007-7162-3 |access-date=18 February 2023|pmc=11136187 }}
Structure
The structure of the HMG-box domain contains three alpha helices separated by loops (see figure to the right).{{cite journal | author = Thomas JO | title = HMG1 and 2: architectural DNA-binding proteins | journal = Biochem. Soc. Trans. | volume = 29 | issue = Pt 4 | pages = 395–401 |date=August 2001 | pmid = 11497996 | doi = 10.1042/BST0290395}}
Function
HMG-box containing proteins only bind non-B-type DNA conformations (kinked or unwound) with high affinity. HMG-box domains are found in some high mobility group proteins, which are involved in the regulation of DNA-dependent processes such as transcription, replication, and DNA repair, all of which require changing the conformation of chromatin.
The single and the double box HMG proteins alter DNA architecture by inducing bends upon binding.D. Murugesapillai et al, [https://doi.org/10.1093/nar/gku635 DNA bridging and looping by HMO1 provides a mechanism for stabilizing nucleosome-free chromatin], Nucleic Acids Res (2014) 42 (14): 8996-9004D. Murugesapillai et al, [https://link.springer.com/article/10.1007/s12551-016-0236-4 Single-molecule studies of high-mobility group B architectural DNA bending proteins], Biophys Rev (2016) doi:10.1007/s12551-016-0236-4
References
{{Reflist}}
External links
- {{MeshName|HMG-Box+Domains|3=HMG-Box Domains}}
Category:DNA-binding substances
Category:Protein superfamilies
{{Protein-stub}}