InterPro domain: IPR031968

The VASt (VAD1 Analog of StAR-related lipid transfer) domain is conservedacross eukaryotes and is structurally related to Bet v1-like domains, including START lipid-binding domains. The~190-amino acid VASt domain is predominantly associated with lipid bindingdomains such as GRAM, C2 and PH domains.The VASt domain is likely to have a function in binding large hydrophobicligands and may be specific for sterol [ 1 , 2 ].

The predicted structure of the VASt domain is a two-layer sandwich alpha betafold, also called "helix grip fold", containing three alpha helices (alpha1 to3), six beta-sheets (beta1 to 6) and two loops (omega1 and 2) numbered from Nto C terminus [ 3 ].

Some proteins known to contain a VASt domain are listed below:

• Plant vascular associated death1 (VAD1), a regulator of programmed cell death (PCD) harboring a GRAM putative lipid-binding domain.
• Yeast SNF1 Interacting Protein 3 (SIP3), may be involved in sterol transfer between intracellular membranes.
• Yeast Suicide Protein 1 (YSP1), a mitochondrial protein specifically required for the mitochondrial thread-grain transition, de-energization, and the cell death. May be involved in sterol transfer between intracellular membranes.
• Yeast Suicide Protein 2 (YSP2), a mitochondrial membrane protein involved in mitochondrial fragmentation. May be involved in sterol transfer between intracellular membranes.
• Human GramD1a-c.

1. Identification and phylogenetic analyses of VASt, an uncharacterized protein domain associated with lipid-binding domains in Eukaryotes. BMC Bioinformatics 15, 222
2. A new family of StART domain proteins at membrane contact sites has a role in ER-PM sterol transport. Elife 4