NUDIX hydrolases are a

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

of hydrolytic

enzymes An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as pro ...

capable of cleaving nucleoside diphosphates linked to x (any moiety), hence their name. The reaction yields nucleoside monophosphate (NMP) plus X-P. Substrates hydrolysed by nudix enzymes comprise a wide range of organic pyrophosphates, including nucleoside di- and triphosphates, dinucleoside and diphosphoinositol polyphosphates, nucleotide sugars and RNA caps, with varying degrees of substrate specificity. Enzymes of the NUDIX superfamily are found in all types of organisms, including eukaryotes, bacteria and archaea. There are two components to the NUDIX family: the so-called NUDIX fold of a beta sheet with alpha helices on each side and the NUDIX motif which contains catalytic and metal-binding

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s. The Nudix motif is GXXXXXEXXXXXXXREUXEEXGU where U is isoleucine, leucine or valine, and X is any amino acid. This forms a short helix which (usually) contains the catalytic amino acids. NUDIX hydrolases include Dcp2 of the

decapping complex The mRNA decapping complex is a protein complex in eukaryotic cells responsible for removal of the 5' cap. The active enzyme of the decapping complex is the bilobed Nudix family enzyme DCP2, Dcp2, which hydrolyzes 5' Cap, 5' cap and releases 7mGD ...

, ADP-ribose diphosphatase, MutT, ADPRase, Ap4A hydrolases, RppH, and many others.

References

{{reflist, 2 Protein superfamilies