4fl0
Crystal structure of ALD1 from Arabidopsis thalianaCrystal structure of ALD1 from Arabidopsis thaliana
Structural highlights
FunctionALD1_ARATH Aminotransferase involved in local and systemic acquired resistance (SAR) to the bacterial pathogen P.syringae. Required for salicylic acid (SA) and camalexin accumulation upon pathogen infection. Possesses aminotransferase activity in vitro and may generate amino-acid-derived defense signals in vivo. May be involved in ethylene-induced senescence signaling.[1] [2] [3] [4] [5] Publication Abstract from PubMedDiaminopimelate aminotransferase (DAP-AT) is an enzyme in the lysine-biosynthesis pathway. Conversely, ALD1, a close homologue of DAP-AT in plants, uses lysine as a substrate in vitro. Both proteins require pyridoxal-5'-phosphate (PLP) for their activity. The structure of ALD1 from the flowering plant Arabidopsis thaliana (AtALD1) was solved at a resolution of 2.3 A. Comparison of AtALD1 with the previously solved structure of A. thaliana DAP-AT (AtDAP-AT) revealed similar interactions with PLP despite sequence differences within the PLP-binding site. However, sequence differences between the binding site of AtDAP-AT for malate, a purported mimic of substrate binding, and the corresponding site in AtALD1 led to different interactions. This suggests that either the substrate itself, or the substrate-binding mode, differs in the two proteins, supporting the known in vitro findings. Structure of ALD1, a plant-specific homologue of the universal diaminopimelate aminotransferase enzyme of lysine biosynthesis.,Sobolev V, Edelman M, Dym O, Unger T, Albeck S, Kirma M, Galili G Acta Crystallogr Sect F Struct Biol Cryst Commun. 2013 Feb 1;69(Pt 2):84-9. doi: , 10.1107/S1744309112050270. Epub 2013 Jan 26. PMID:23385743[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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