CRAL-TRIO domain
Protein domain
From Wikipedia, the free encyclopedia
CRAL-TRIO domain is a protein structural domain that binds small lipophilic molecules.[2] This domain is named after cellular retinaldehyde-binding protein (CRALBP) and TRIO guanine exchange factor.
| CRAL/TRIO domain | |||||||
|---|---|---|---|---|---|---|---|
Alpha-tocopherol transfer protein, closed state with ligand.[1] | |||||||
| Identifiers | |||||||
| Symbol | CRAL_TRIO | ||||||
| Pfam | PF00650 | ||||||
| InterPro | IPR001251 | ||||||
| SMART | Sec14 | ||||||
| SCOP2 | 1aua / SCOPe / SUPFAM | ||||||
| OPM superfamily | 121 | ||||||
| OPM protein | 1r5l | ||||||
| CDD | cd00170 | ||||||
| Membranome | 576 | ||||||
| |||||||
CRALB protein carries 11-cis-retinol or 11-cis-retinaldehyde. It modulates interaction of retinoids with visual cycle enzymes. TRIO is involved in coordinating actin remodeling, which is necessary for cell migration and growth.
Other members of the family are alpha-tocopherol transfer protein and phosphatidylinositol-transfer protein (Sec14). They transport their substrates (alpha-tocopherol and phosphatidylinositol or phosphatidylcholine, respectively) between different intracellular membranes. Family also include a guanine nucleotide exchange factor that may function as an effector of RAC1 small G-protein.
The N-terminal domain of yeast ECM25 protein has been identified as containing a lipid binding CRAL-TRIO domain.[3]
Structure
The Sec14 protein was the first CRAL-TRIO domain for which the structure was determined.[4] The structure contains several alpha helices as well as a beta sheet composed of 6 strands. Strands 2,3,4 and 5 form a parallel beta sheet with strands 1 and 6 being anti-parallel. The structure also identified a hydrophobic binding pocket for lipid binding.
