Sso6206, a 10.5 kDa protein from Sulfolobus solfataricus, has been overexpressed, purified and crystallized. The protein crystallizes in space group P6(1/5)22, with unit-cell parameters a = b = 157.8, c = 307.3 A. The crystals are hexagonal bipyramids and a data set has been collected to 2.4 A resolution. Molecular replacement cannot be attempted as no convincing model can be identified. Crysta...

Chemical biotinylation of protein complexes followed by binding to two-dimensional (monolayer) crystals of streptavidin is shown to be an effective way to prepare cryo-EM specimens from samples at low protein concentration. Three different multiprotein complexes are used to demonstrate the generality of this method. In addition, native thermosomes, purified from Sulfolobus solfataricus P2, are ...

A sulfite-activated ATPase isolated from Sulfolobus solfataricus had a relative molecular mass of 370,000. It was composed of three subunits whose relative molecular masses were 63,000, 48,000, and 24,000. The enzyme was inhibited by the vacuolar ATPase inhibitors nitrate and N-ethylmaleimide; 4-chloro-7-nitrobenzofurazan (NBD-Cl) was also inhibitory. N-Ethylmaleimide was predominately bound to...

Sulfolobus solfataricus is a hyperthermophilic archaeon growing optimally at 80-85 degrees C. It metabolizes glucose via a novel non-phosphorylated Entner-Doudoroff pathway, in which the reversible C(6) to C(3) aldol cleavage is catalysed by 2-keto-3-deoxygluconate aldolase (KDG-aldolase), generating pyruvate and glyceraldehyde. Given the ability of such a hyperstable enzyme to catalyse carbon-...

Aldolases are enzymes with potential applications in biosynthesis, depending on their activity, specificity and stability. In the present study, the genomes of Sulfolobus species were screened for aldolases. Two new KDGA [2-keto-3-deoxygluconate (2-oxo-3-deoxygluconate) aldolases] from Sulfolobus acidocaldarius and Sulfolobus tokodaii were identified, overexpressed in Escherichia coli and chara...

We have detected two paralogs of the tRNA endonuclease gene of Methanocaldococcus jannaschii in the genome of the crenarchaeote Sulfolobus solfataricus. This finding has led to the discovery of a previously unrecognized oligomeric form of the enzyme. The two genes code for two different subunits, both of which are required for cleavage of the pre-tRNA substrate. Thus, there are now three forms ...

The trimeric translation initiation factor a/eIF2 of the crenarchaeon Sulfolobus solfataricus is pivotal for binding of initiator tRNA to the ribosome. Here, we present in vitro and in vivo evidence that the a/eIF2 gamma-subunit exhibits an additional function with resemblance to the eukaryotic cap-complex. It binds to the 5'-triphosphate end of mRNA and protects the 5' part from degradation. T...

A predicted GTP-binding protein from the hyperthermophilic archaeon Sulfolobus solfataricus, termed SsGBP, has been cloned and overexpressed in Escherichia coli. The purified protein was crystallized using the hanging-drop vapour-diffusion technique in the presence of 0.05 M cadmium sulfate and 0.8 M sodium acetate pH 7.5. A single-wavelength anomalous dispersion data set was collected to a max...