In Euryarchaeota the reaction is catalysed by ArcS [1,2]. 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 [2]. The enzyme from the Euryarchaeon?Methanocaldococcus jannaschii?can also use arginine and ammonium as amino donors.
Cofactor
History
Reactions
L-glutamine + 7-cyano-7-carbaguanine(15) in tRNA + H(2)O = L-glutamate + archaeine(15) in tRNA.
