ENTRY       EC 3.5.4.19
NAME        Phosphoribosyl-AMP cyclohydrolase
CLASS       Hydrolases
            Acting on carbon-nitrogen bonds, other than peptide bonds
            In cyclic amidines
SYSNAME     N1-(5-Phospho-D-ribosyl)-AMP 1,6-hydrolase
REACTION    N1-(5-Phospho-D-ribosyl)-AMP + H2O =
            5-(5-Phospho-D-ribosylaminoformimino)-1-(5-phosphoribosyl)-
            $imidazole-4-carboxamide
SUBSTRATE   N1-(5-Phospho-D-ribosyl)-AMP
            H2O
PRODUCT     5-(5-Phospho-D-ribosylaminoformimino)-1-(5-phosphoribosyl)-
            $imidazole-4-carboxamide
COMMENT     The Neurospora crassa enzyme also catalyses the reactions of
            EC 1.1.1.23 and 3.6.1.31.
            (EC 1.1.1.23 Histidinol dehydrogenase)
            (EC 3.6.1.31 Phosphoribosyl-ATP pyrophosphatase)
PATHWAY     PATH: MAP00340  Histidine metabolism
MOTIF       PS: PS00611  I-D-x(2)-A-G-P-[ST]-E-[LIVMA](5)-x(3)-A-x(4)-[LIVM]-
                         [AV]-[SA]-D-[LIVM](2)-[SA]-x-A-E-H
GENES       MJA: MJ0302(hisE) MJ1430
            MTH: MTH245
            ECO: b2026(hisI)
            HIN: HI0475(hisI)
            BSU: hisI(hisIE)
            SYN: slr0608(hisI)
            SCE: YCL030C(HIS4)
DBLINKS     University of Geneva ENZYME DATA BANK: 3.5.4.19
            WIT (What Is There) Metabolic Reconstruction: 3.5.4.19
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