Task: Text Categorization
Input (English): One system of their classification divides them into minor, replication-dependent, and replication-independent types. In the lab, they are isolated by cleavage of the source material followed by salt elution in a hydroxyapatite column. They never contain tryptophan and are usually rich in lysine and arginine. A type found in Euryarchaea may be the evolutionary precursor to those found in eukaryotes. Four of their classes form an octameric nucleosome, while the linker or H1 type regulates the formation of thirty-nanometer fibers. FTP, name this class of proteins which forms chromatin when DNA coils around them.
Output (English): Science