6pbr

Publication Abstract from PubMed

The crystallization of amidase, the ultimate enzyme in the Trp-dependent auxin-biosynthesis pathway, from Arabidopsis thaliana was attempted using protein samples with at least 95% purity. Cube-shaped crystals that were assumed to be amidase crystals that belonged to space group I4 (unit-cell parameters a = b = 128.6, c = 249.7 A) were obtained and diffracted to 3.0 A resolution. Molecular replacement using structures from the PDB containing the amidase signature fold as search models was unsuccessful in yielding a convincing solution. Using the Sequence-Independent Molecular replacement Based on Available Databases (SIMBAD) program, it was discovered that the structure corresponded to dihydrolipoamide succinyltransferase from Escherichia coli (PDB entry 1c4t), which is considered to be a common crystallization contaminant protein. The structure was refined to an Rwork of 23.0% and an Rfree of 27.2% at 3.0 A resolution. The structure was compared with others of the same protein deposited in the PDB. This is the first report of the structure of dihydrolipoamide succinyltransferase isolated without an expression tag and in this novel crystal form.

Structure of the dihydrolipoamide succinyltransferase catalytic domain from Escherichia coli in a novel crystal form: a tale of a common protein crystallization contaminant.,Andi B, Soares AS, Shi W, Fuchs MR, McSweeney S, Liu Q Acta Crystallogr F Struct Biol Commun. 2019 Sep 1;75(Pt 9):616-624. doi:, 10.1107/S2053230X19011488. Epub 2019 Aug 29. PMID:31475929^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.