Extensive crystallization trials of Aspergillus nidulans dehydroquinate syn
thase, a potential novel target for antimicrobial drugs, in complexes with
different ligands have resulted in the identification of nine crystal forms
. Crystals of unliganded DHQS, binary complexes with either the substrate a
nalogue, carbaphosphonate or the cofactor NADH, as well as the ternary DHQS
-carbaphosphonate-cofactor complex, were obtained. The ternary complex crys
tallizes from ammonium sulfate and CoCl2 in space group P2(1)2(1)2, with un
it-cell parameters a = 133.8, b = 86.6, c = 74.9 Angstrom. The binary carba
phosphonate complex crystallizes from PEG 6000 in space group P2(1)2(1)2(1)
, with a = 70.0, b = 64.0, c = 197.6 Angstrom, and the binary cofactor comp
lex crystallizes from PEG 3350 and sodium potassium tartrate in space group
P2(1), with a = 83.7, b = 70.4, c = 144.3 Angstrom, beta = 89.2 degrees. D
HQS in the absence of ligands crystallizes in space group P2(1), with a = 4
1.0, b = 68.9, c = 137.7 Angstrom, beta = 94.8 degrees. Each of these cryst
al forms are suitable for high-resolution structure determination. Structur
es of a range of DHQS-ligand complexes will be of value in the structure-ba
sed design of novel antimicrobial drugs.