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Enoyl-acyl carrier protein reductase (ENR) catalyzes the NADH-dependent stereospecific reduction of alpha,beta-unsaturated fatty acids bound to the acyl-carrier protein. ENR from Helicobacter pylori has been overexpressed in Escherichia coli and has been crystallized in the presence of its cofactor NADH and the inhibitor triclosan (or its analogue diclosan) at 296 K using polyethylene glycol (PEG) 400 as a precipitant. For the triclosan (or diclosan) complex, diffraction data to 2.5 (or 2.3) A resolution have been collected using synchrotron X-rays. The crystals belong to the monoclinic space group P2(1), with unit-cell parameters a = 73.35, b = 94.91, c = 75.38 A, beta = 106.21 degrees for the triclosan complex (or a = 73.25, b = 95.07, c = 75.02 A, beta = 106.53 degrees for the diclosan complex). The asymmetric unit contains one homotetramer, with a corresponding V(M) of 2.10 A(3) Da(-1) and a solvent content of 41% by volume.

Lipid A, a constituent of lipopolysaccharides, is essential for the growth and virulence of most Gram-negative bacteria. This makes its biosynthetic enzymes potential targets for development of new antibacterial agents. The first step of lipid A biosynthesis is catalyzed by the enzyme UDP-N-acetylglucosamine acyltransferase (LpxA). LpxA from the pathogenic bacterium Helicobacter pylori has been overexpressed in Escherichia coli and crystallized at 297 K using ammonium sulfate and sodium/potassium tartrate as precipitants in the presence of a detergent. Diffraction data to 2.1 A resolution have been collected from a native crystal. The crystal belongs to space group P6(3)22, with unit-cell parameters a = b = 90.69, c = 148.20 A. The asymmetric unit contains one subunit of LpxA, with a crystal volume per protein mass (V(M)) of 2.87 A(3) Da(-1) and a solvent content of 57.1%.

A 110-residue protein encoded by the TM1442 gene of Thermotoga maritima shows amino-acid sequence similarity to Bacillus subtilis anti-anti-sigma factors RsbV and SpoIIAA. It has been overexpressed in Escherichia coli and the recombinant protein exists primarily as both a monomer and a dimer in solution. The dimeric form has been crystallized using polyethylene glycol (PEG) 8000 as a precipitant. Native X-ray diffraction data have been collected at 100 K to 2.0 A resolution. The crystals are monoclinic, belonging to the space group P2(1), with unit-cell parameters a = 31.54 (13), b = 116.83 (37), c = 31.39 (7) A, alpha = 90, beta = 119.84 (9), gamma = 90 degrees. The asymmetric unit contains two monomers of the recombinant polypeptide, with a corresponding V(M) of 2.24 A(3) Da(-1) and a solvent content of 45.0%.

The genome of Bacillus subtilis contains three different genes encoding RNase H homologs: RNases HI, HII and HIII. RNase HIII from B. subtilis degrades RNA in RNA-DNA hybrids in an Mg(2+)-dependent manner like Escherichia coli RNase HI. However, they belong to different classes; the former belongs to the 'class II' or 'large' RNase H family, while the latter belongs to the 'class I' or 'small' RNase H family. RNase HIII of B. subtilis has been overexpressed in E. coli and crystallized at 296 K using sodium formate as a precipitant. The native X-ray diffraction data have been collected to 2.8 A resolution using synchrotron radiation. The crystals are hexagonal, belonging to the space group P6(1), with unit-cell parameters a = b = 86.89, c = 214.49 A, alpha = beta = 90.0, gamma = 120.0 degrees. A self-rotation function calculation indicated the presence of two monomers of the recombinant RNase HIII in the crystallographic asymmetric unit, giving a V(M) of 3.43 A(3) Da(-1) and a solvent content of 64.2%.

The enzyme 3-dehydroquinase catalyzes the interconversion of 3-dehydroquinate and 3-dehydroshikimate. The enzymes are classified into two groups, type I and type II, which have different biochemical and biophysical properties and act with different mechanisms. The type II dehydroquinase of Helicobacter pylori, a dodecameric enzyme, was overexpressed in Escherichia coli. The recombinant protein has been crystallized at 296 K using polyethylene glycol (PEG) 4000 as a precipitant. Native X-ray diffraction data have been collected to 2.5 A resolution using synchrotron radiation. The crystals are cubic and belong to the space group P4(2)32, with unit-cell parameters a = b = c = 98.91 A. The asymmetric unit contains one subunit of recombinant type II dehydroquinase, with a corresponding V(M) of 2.18 A(3) Da(-1) and a solvent content of 43.6%.