Description
In Euryarchaeota the reaction is catalysed by ArcS. In Crenarchaeota, which do not have an ArcS homologue, the reaction is catalysed either by a homologue of EC 6.3.4.20, 7-cyano-7-deazaguanine synthase that includes a glutaminase domain (cf. EC 3.5.1.2), or by a homologue of EC 1.7.1.13, preQ1 synthase. The enzyme from the Euryarchaeon Methanocaldococcus jannaschii can also use arginine and ammonium as amino donors