HEAT repeat
| HEAT repeat | |||||||
|---|---|---|---|---|---|---|---|
An example of an alpha solenoid structure composed of 15 HEAT repeats. The protein phosphatase 2A regulatory subunit is shown with the N-terminus in blue at bottom and the C-terminus in red at top. A single helix-turn-helix motif is shown in the center with the outer helix in pink, the inner helix in green, and the turn in white. From PDB: 2IAE. | |||||||
| Identifiers | |||||||
| Symbol | HEAT | ||||||
| Pfam | PF02985 | ||||||
| InterPro | IPR000357 | ||||||
| PROSITE | PDOC50077 | ||||||
| SCOP2 | 1b3u / SCOPe / SUPFAM | ||||||
| |||||||
A HEAT repeat is a protein tandem repeat structural motif composed of two alpha helices linked by a short loop. HEAT repeats can form alpha solenoids, a type of solenoid protein domain found in a number of cytoplasmic proteins. The name "HEAT" is an acronym for four proteins in which this repeat structure is found: Huntingtin, elongation factor 3 (EF3), protein phosphatase 2A (PP2A), and the yeast kinase TOR1. HEAT repeats form extended superhelical structures which are often involved in intracellular transport; they are structurally related to armadillo repeats. The nuclear transport protein importin beta contains 19 HEAT repeats.