InterPro domain: IPR031206

This family of plant proteins includes the protein HOTHEAD (HTH), an enzyme involved in regulating organ fusion. HTH is required to limit cellular interactions between contacting epidermal cells during floral development [ 1 ]. HTH is expressed ubiquitously in root and shoot tissues and is not limited to the epidermis. It is involved in the biosynthesis of long-chain alpha-, omega-dicarboxylic fatty acids, probably acting in the step after cytochrome P450 FA omega-hydroxylases in the omega-oxidation pathway [ 2 ]. HTH has similarity to the mandelonitrile lyase family of FAD containing oxidoreductases. In rice HOTHEAD-Like HTH1 appears to be required for pollen fertility [ 3 ].

1. Isolation and characterization of the Arabidopsis organ fusion gene HOTHEAD. Plant J. 35, 501-11
2. Genetic and biochemical evidence for involvement of HOTHEAD in the biosynthesis of long-chain alpha-,omega-dicarboxylic fatty acids and formation of extracellular matrix. Planta 224, 315-29
3. HOTHEAD-Like HTH1 is Involved in Anther Cutin Biosynthesis and is Required for Pollen Fertility in Rice. Plant Cell Physiol. 58, 1238-1248