Protein Family Models

This domain composes the whole protein of methylglyoxal synthetase and the domain is also found in Carbamoyl phosphate synthetase (CPS) where it forms a regulatory domain that binds to the allosteric effector ornithine. This family also includes inosicase. The known structures in this family show a common phosphate binding site [1]. [1]. 10526357. Structure classification-based assessment of CASP3 predictions for the fold recognition targets. Murzin AG;. Proteins 1999;37:88-103. (from Pfam)

Date:

2024-10-16

This is a family of bifunctional enzymes catalysing the last two steps in de novo purine biosynthesis. The bifunctional enzyme is found in both prokaryotes and eukaryotes. The second last step is catalysed by 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase EC:2.1.2.3 (AICARFT), this enzyme catalyses the formylation of AICAR with 10-formyl-tetrahydrofolate to yield FAICAR and tetrahydrofolate [1]. This is catalysed by a pair of C-terminal deaminase fold domains in the protein [3], where the active site is formed by the dimeric interface of two monomeric units [3]. The last step is catalysed by the N-terminal IMP (Inosine monophosphate) cyclohydrolase domain EC:3.5.4.10 (IMPCHase), cyclizing FAICAR (5-formylaminoimidazole-4-carboxamide ribonucleotide) to IMP [1]. [1]. 9332377. Molecular cloning and expression of a rat cDNA encoding 5- aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase [published erratum appears in Gene 1998 Feb 27;208(2):337]. Akira T, Komatsu M, Nango R, Tomooka A, Konaka K, Yamauchi M, Kitamura Y, Nomura S, Tsukamoto I;. Gene 1997;197:289-293. [2]. 8567683. The human purH gene product, 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase. Cloning, sequencing, expression, purification, kinetic analysis, and domain mapping. Rayl EA, Moroson BA, Beardsley GP;. J Biol Chem 1996;271:2225-2233. [3]. 21890906. Evolution of the deaminase fold and multiple origins of eukaryotic editing and mutagenic nucleic acid deaminases from bacterial toxin systems. Iyer LM, Zhang D, Rogozin IB, Aravind L;. Nucleic Acids Res. 2011; [Epub ahead of prin. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

phosphoribosylaminoimidazolecarboxamide formyltransferase formylates 5-aminoimidazole-4-carboxamide-ribonucleotide which is then converted to inosine monophosphate by inosine monophosphate cyclohydrolase

Date:

2024-10-23

Gene:

purH

Date:

2021-07-21

PurH is bifunctional: IMP cyclohydrolase (EC 3.5.4.10); phosphoribosylaminoimidazolecarboxamide formyltransferase (EC 2.1.2.3) Involved in purine ribonucleotide biosynthesis. The IMP cyclohydrolase activity is in the N-terminal region.

Gene:

purH

Date:

2021-04-27