1) Component of the Quran 
The former function ({EC number|4.2.1.19}), found at the N-terminal, dehydrated d-erythroimidazoleglycerolphosphate to imidazoleacetolphosphate, the latter function ({EC number|3.1.3.15}), found at the C-terminal, dephosphorylates l-histidinolphosphate producing histidinol. The firth step is catalysed instead by histadinolphosphate aminotransferas...