3BWN

L-tryptophan aminotransferase

Summary for 3BWN

• Entry DOI: 10.2210/pdb3bwn/pdb
• Related: 3BWO
• Descriptor: L-tryptophan aminotransferase, 4'-DEOXY-4'-AMINOPYRIDOXAL-5'-PHOSPHATE, PHOSPHATE ION, ... (6 entities in total)
• Functional Keywords: aminotransferase, auxin synthesis, tryptophan, pyridoxal-5'-phosphate, indole-3-pyruvate, transferase
• Biological source: Arabidopsis thaliana (thale cress); More
• Cellular location: Cytoplasm: Q9S7N2 Q9S7N2
• Total number of polymer chains: 6
• Total formula weight: 270665.09

Authors

Ferrer, J.-L.,Noel, J.P.,Pojer, F.,Bowman, M.,Chory, J.,Tao, Y. (deposition date: 2008-01-10, release date: 2008-04-29, Last modification date: 2023-11-15)

Primary citation

Tao, Y.,Ferrer, J.L.,Ljung, K.,Pojer, F.,Hong, F.,Long, J.A.,Li, L.,Moreno, J.E.,Bowman, M.E.,Ivans, L.J.,Cheng, Y.,Lim, J.,Zhao, Y.,Ballare, C.L.,Sandberg, G.,Noel, J.P.,Chory, J.
Rapid synthesis of auxin via a new tryptophan-dependent pathway is required for shade avoidance in plants
Cell(Cambridge,Mass.), 133:164-176, 2008

PubMed Abstract: Plants grown at high densities perceive a decrease in the red to far-red (R:FR) ratio of incoming light, resulting from absorption of red light by canopy leaves and reflection of far-red light from neighboring plants. These changes in light quality trigger a series of responses known collectively as the shade avoidance syndrome. During shade avoidance, stems elongate at the expense of leaf and storage organ expansion, branching is inhibited, and flowering is accelerated. We identified several loci in Arabidopsis, mutations in which lead to plants defective in multiple shade avoidance responses. Here we describe TAA1, an aminotransferase, and show that TAA1 catalyzes the formation of indole-3-pyruvic acid (IPA) from L-tryptophan (L-Trp), the first step in a previously proposed, but uncharacterized, auxin biosynthetic pathway. This pathway is rapidly deployed to synthesize auxin at the high levels required to initiate the multiple changes in body plan associated with shade avoidance.

PubMed: 18394996
DOI: 10.1016/j.cell.2008.01.049

Experimental method

X-RAY DIFFRACTION (2.25 Å)