The TER ATPase is an ATPase enzyme present in all eukaryotes and archaebacteria. Subtilase is widespread, being found in eubacteria, archaebacteria, eukaryotes and viruses. Otto Kandler's main subject in microbiology was his research on "archaea" (before 1990 called "archaebacteria"). He classifies the groups which he believes are younger (archaebacteria and eukaryotes) as Neomura. PPE has been found in a wide range of bacteria, archaebacteria, fungi and plants. Class III reductases are distributed in archaebacteria, eubacteria, and bacteriophages. Class II reductases are distributed in archaebacteria, eubacteria, and bacteriophages. The functions of the topoisomerases in archaebacteria are comparable to the enzymes in eubacteria. However, in archaebacteria these genes are non-adjacent and exhibit no linkage. They are known to be the most common archaebacteria in deep subterranean habitats. Histone-like proteins are present in many Eubacteria, Cyanobacteria, and Archaebacteria. Gold claimed that the sludge contained both oil and remnants of archaebacteria. It is commonly found in Eubacteria, Archaebacteria, Protista, Fungi, and Plantae. Tryptophan synthase is commonly found in Eubacteria, Archaebacteria, Protista, Fungi, and Plantae. The Bacteria (= prokaryotes) are subdivided into Eubacteria and Archaebacteria.