Kenya which converts starch to cyclodextrins. The responsible thermostable enzyme, CGTase, is active at a broad pH range and produces preferentially α-cyclodextrins.
In order to study structure-function relationships of heat-stable enzymes from extremophiles, experiments were performed using intrinsic fluorescence and far-ultraviolet CD measurements. Significant structural changes of pullulanase and glutamate dehydrogenase from P. woesei were also observed under hydrostatic pressure (up to 4000 bar) at elevated temperatures.
Recently, the DNA polymerase from a newly isolated hyperthermophile (Thermococcus aggregans) was characterized in detail. The gene has been cloned from the chromosomal DNA by PCR screening and the corresponding enzyme was overexpressed in E. coli. Sequence comparison of the gene with related DNA polymerase genes revealed that it is interrupted by three regions showing high homologies to self-splicing protein elements, so called "inteins". The archaeal enzyme shows DNA polymerase and 3'-5' exnouclease activity at high temperature, being a promising candidate in the performance of the polymerase chain reaction (PCR).
