 HEAT Domain | |
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Structure:
 The HEAT domain consists of repeats of two anti-parallel α-helices and two turns arranged about a common axis. These repeats are linked by flexible inter-unit loops. A signature motif of the HEAT repeats is the presence of conserved Asp and Arg residues at positions 19 and 25, respectively.
Structure Reference:Groves, M.R. et al. (1999) Cell. 96(1): 99-110. Vetter, I.R. et al. (1999) Cell. 97(5): 635-646. PDB: 1IBR.
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Domain binding and function:
The protein domain HEAT (Huntington, Elongation Factor 3, PR65/A, TOR) was derived from four diverse eukaryotic proteins. The HEAT domain consists of repeats of ~47 residues that form two anti-parallel α-helices and two turns arranged about a common axis. A signature motif of the HEAT repeats is the presence of conserved Asp and Arg residues at positions 19 and 25, respectively. Similarities between HEAT and Armadillo (ARM) repeat families are found in the conserved residues that form the hydrophobic cores. In constrast to ARM repeats, HEAT repeats are more variable in length, amino acid sequence and 3D-structure. Family of HEAT repeats are divided into three classes: IMB, AAA and ADB based on similarities. HEAT containing proteins are found in proteins such as importins and exportins that bind Ran-GTP implicating their role in cargo transport. A substantial number of HEAT repeats have been detected in proteins involved in translation including eIF4Gs, p97/DAP5, Paip-1, GCN1 and FRAP/mTOR.
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Examples of Proteins:
| HEAT domain proteins |
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Binding partners |
PA200
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Ecm29
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| PR65/A |  |
PP2Ac and B subunits |
TOR
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NOC3P
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| Importins β1 | |
Ran-GTP |
Importins β2
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SAP155
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Cse1, exportin
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eIF5
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| eIF4GII | |
eIF5 |
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Referenced in part on Cell Signaling Technology Website, Reference Section on Protein Domains. We gratefully acknowledge the following contributors:
Piers Nash1, Dan Lin3, Kathleen Binns2, Clark Wells2, Rob Ingham2, Terry Kubiseski2, Bernard Liu1, Matt Smith2,3, Ivan Blasutig2,3, Maria Sierra1, Caesar Lim2,3, Michael Arc1, Jim Fawcett2 and Tony Pawson2,3.
1. Ben May Institute for Cancer Research, The University of Chicago, Chicago, Illinois, 60637, USA
2. Program in Molecular Biology and Cancer, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada
3. Department of Molecular and Medical Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
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