Interaction of FLU, a negative regulator of tetrapyrrole biosynthesis, with the glutamyl-tRNA reductase requires the tetratricopeptide repeat domain of FLU.
Regulation of tetrapyrrole biosynthesis in plants has been attributed to feedback control of glutamyl-tRNA reductase (GLU-TR) by heme. Recently, another negative regulator, the FLU protein, has been discovered that operates independently of heme. A truncated form of FLU that contains two domains implicated in protein-protein interaction was co-expressed in yeast with either GLU-TR or glutamate-1-semialdehyde-2-1-aminotransferase (GSA-AT), the second enzyme involved in delta-aminolevulinic acid (ALA) biosynthesis. FLU interacts strongly with GLU-TR but not with GSA-AT. Two variants of FLU that carry single amino acid exchanges within their coiled coil and tetratricopeptide repeat (TPR) domains, respectively, were also tested. Only the FLU variant with the mutated TPR motif lost the capacity to interact with GLU-TR.
Meskauskiene
Rasa
R
Institute of Plant Sciences, Swiss Federal Institute of Technology (ETH), Universitätstr. 2, 8092 Zürich, Switzerland.
Apel
Klaus
K
D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology; D019751:Intramolecular Transferases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011758:Pyrroles / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid; D045725:Tetrapyrroles; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; D011758:Pyrroles; D045725:Tetrapyrroles; D000445:Aldehyde Oxidoreductases; C067282:glutamyl tRNA reductase; D019751:Intramolecular Transferases; C061049:glutamate-1-semialdehyde 2,1-aminomutase