The NACHT domain is an evolutionarily conserved

protein domain In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist o ...

. This

NTPase In enzymology, a nucleoside-triphosphatase (NTPase) () is an enzyme that catalyzes the chemical reaction :NTP + H2O \rightleftharpoons NDP + phosphate Thus, the two substrates of this enzyme are NTP and H2O, whereas its two products are NDP a ...

domain is found in apoptosis

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

s as well as those involved in MHC transcription. Its name reflects some of the proteins that contain it: NAIP (NLP family apoptosis

inhibitor protein The inhibitor protein (IP) is situated in the mitochondrial matrix and protects the cell against rapid ATP hydrolysis during momentary ischaemia Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ ...

), CIITA (that is, C2TA or MHC class II transcription activator), HET-E (incompatibility locus protein from ''Podospora anserina'') and TEP1 (that is, TP1 or telomerase-associated protein). The NACHT domain contains 300 to 400

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...

s. It is a predicted

nucleoside-triphosphatase In enzymology, a nucleoside-triphosphatase (NTPase) () is an enzyme that catalyzes the chemical reaction :NTP + H2O \rightleftharpoons NDP + phosphate Thus, the two substrates of this enzyme are NTP and H2O, whereas its two products are NDP ...

(NTPase) domain, which is found in

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

, fungal and

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

l proteins. It is found in association with other domains, such as the

CARD domain Caspase recruitment domains, or caspase activation and recruitment domains (CARDs), are interaction motifs found in a wide array of proteins, typically those involved in processes relating to inflammation and apoptosis. These domains mediate t ...

(), the pyrin domain (), the HEAT repeat domain (), the WD40 repeat (), the leucine-rich repeat (LRR) or the

BIR repeat The inhibitor of apoptosis domain -- also known as IAP repeat, Baculovirus Inhibitor of apoptosis protein Repeat, or BIR -- is a structural motif found in proteins with roles in apoptosis, cytokine production, and chromosome segregation. Proteins c ...

(). The NACHT domain consists of seven distinct conserved motifs, including the ATP/GTPase specific P-loop, the Mg²⁺-binding site ( Walker A and B motifs, respectively) and five more specific motifs. The unique features of the NACHT domain include the prevalence of 'tiny' residues (glycine, alanine or serine) directly C-terminal of the Mg²⁺-coordinating aspartate in the Walker B motif, in place of a second acidic residue prevalent in other NTPases. A second acidic residue is typically found in the NACHT-containing proteins two positions downstream. Furthermore, the distal motif VII contains a conserved pattern of polar, aromatic and hydrophobic residues that is not seen in any other NTPase family.

Examples

Human proteins containing this domain include: * CIITA * NAIP * NLRC3,

NLRC4 NLR family CARD domain-containing protein 4 is a protein that in humans is encoded by the ''NLRC4'' gene. Structure The NLRC4 protein is highly conserved across mammalian species. It bears homology to the ''C. elegans'' Ced4 protein. It contai ...

, NLRC5 * NLRP1, NLRP2,

NLRP3 NLR family pyrin domain containing 3 (NLRP3) (previously known as NACHT, LRR and PYD domains-containing protein 3 ALP3and cryopyrin), is a protein that in humans is encoded by the ''NLRP3'' gene located on the long arm of chromosome 1. NLRP3 is ...

, NLRP4, NLRP5, NLRP6,

NLRP7 NACHT, LRR and PYD domains-containing protein 7 is a protein that in humans is encoded by the ''NLRP7'' gene. Function NALPs are cytoplasmic proteins that form a subfamily within the larger CATERPILLER protein family. Most short NALPs, such a ...

NLRP8 NLRP8, short for NOD-like receptor family pyrin domain containing 8, is an intracellular protein that is expressed in the ovaries, testes, and pre implantation embryos of mammals. It is also known as NALP8, NOD16, PAN4, and CLR19.2, and is one o ...

NLRP9 NLRP9, short for NOD-like receptor family pyrin domain containing 9, is an intracellular protein that is expressed in the ovaries, testes, oocytes, and pre implantation embryos of mammals that is likely involved in reproductive processes. It is ...

NLRP10 NLRP10, short for NOD-like receptor family pyrin domain containing 10, is an intracellular protein of mammals that functions in apoptosis and the immune system. It is also known as NALP10, NOD8, PAN5, Pynod, and CLR11.1, and is one of 14 pyrin d ...

NLRP11 NOD-like receptor family pyrin domain containing 11 is a protein that in humans is encoded by the NLRP11 gene located on the long arm of human chromosome 19q13.42. NLRP11 belongs to the NALP subfamily, part of a large subfamily of caterpiller. It ...

NLRP12 NACHT, LRR and PYD domains-containing protein 12 is a protein that in humans is encoded by the ''NLRP12'' gene. NALPs are cytoplasmic proteins that form a subfamily within the larger CATERPILLER protein family. Most short NALPs, such as NALP12, ...

NLRP13 NLRP13, short for NOD-like receptor family pyrin domain containing 13, is an intracellular protein of mammals. It is also known as NALP13, NOD14, PAN13, and CLR19.7, and is one of 14 pyrin domain containing members of the NOD-like receptor famil ...

NLRP14 NLRP14, short for NOD-like receptor family pyrin domain containing 14, is an intracellular protein of mammals associated with a role in spermatogenesis. It is also known as NALP14, NOD5, GC-LRR, Nalp-iota, PAN8, and CLR11.2, and is one of 14 pyr ...

, NLRX1 * NOD1,

NOD2 Nucleotide-binding oligomerization domain-containing protein 2 (NOD2), also known as caspase recruitment domain-containing protein 15 (CARD15) or inflammatory bowel disease protein 1 (IBD1), is a protein that in humans is encoded by the ''NOD2'' g ...

* NWD1 * TEP1

References

Protein domains {{InterPro content, IPR007111