Thymoquinone blocks pSer/pThr recognition by Plk1 Polo-box domain as a phosphate mimic.

Phosphorylation-dependent protein-protein interaction has rarely been targeted in medicinal chemistry. Thymoquinone, a naturally occurring antitumor agent, disrupts prephosphorylated substrate recognition by the polo-box domain of polo-like kinase 1, a key mitotic regulator responsible for various carcinogenesis when overexpressed. Here, crystallographic studies reveal that the phosphoserine/phosphothreonine recognition site of the polo-box domain is the binding pocket for thymoquinone and its analogue poloxime.

Characterization and tissue-specific expression of two lepidopteran farnesyl diphosphate synthase homologs: implications for the biosynthesis of ethyl-substituted juvenile hormones.

The sesquiterpenoid juvenile hormone (JH) regulates insect development and reproduction. Most insects produce only one chemical form of JH, but the Lepidoptera produce four derivatives featuring ethyl branches. The biogenesis of these JHs requires the synthesis of ethyl-substituted farnesyl diphosphate (FPP) by FPP synthase (FPPS).

Compact reduced thioredoxin structure from the thermophilic bacteria Thermus thermophilus.

The X-ray crystallographic structure of a thioredoxin from Thermus thermophilus was solved to 1.8 A resolution by molecular replacement. The crystals' space group was C2 with cell dimensions of a = 40.

Crystal structure of a purine/pyrimidine phosphoribosyltransferase-related protein from Thermus thermophilus HB8.

Adenine phosphoribosyltransferase (APRTase) is a widely distributed enzyme involved in the salvage of adenine to form an adenine nucleotide. We crystallized and determined the X-ray crystallographic structure of a purine/pyrimidine phosphoribosyltransferase-related protein from the thermophilic bacterium, Thermus thermophilus HB8. The crystal space group was C2 with unit cell dimensions of a = 167.

Structure of a putative 2'-5' RNA ligase from Pyrococcus horikoshii.

Cyclic phosphodiesterase and 2'-5' RNA ligase are members of a superfamily of proteins which share structural similarities even though their homology may be very low. A putative 2'-5' RNA ligase from Pyrococcus horikoshii has been crystallized and its X-ray crystallographic structure determined to 2.4 A.