Open AccessStructure of ALD1, a plant‐specific homologue of the universal diaminopimelate aminotransferase enzyme of lysine biosynthesis
Author(s) -
Sobolev Vladimir,
Edelman Marvin,
Dym Orly,
Unger Tamar,
Albeck Shira,
Kirma Menny,
Galili Gad
Publication year - 2013
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309112050270
Subject(s) - arabidopsis thaliana , biosynthesis , lysine , biochemistry , enzyme , pyridoxal phosphate , binding site , pyridoxal , biology , substrate (aquarium) , in vitro , active site , lyase , stereochemistry , chemistry , amino acid , gene , cofactor , mutant , ecology
Diaminopimelate 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 ( At ALD1) was solved at a resolution of 2.3 Å. Comparison of At ALD1 with the previously solved structure of A. thaliana DAP‐AT ( At DAP‐AT) revealed similar interactions with PLP despite sequence differences within the PLP‐binding site. However, sequence differences between the binding site of At DAP‐AT for malate, a purported mimic of substrate binding, and the corresponding site in At ALD1 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.