PROSITE documentation PDOC50837

NACHT-NTPase domain profile

The NACHT domain is a 300 to 400 residue predicted nucleoside triphosphatase (NTPase) domain, which is found in animal, fungal and bacterial proteins. The NACHT domain has been named after NAIP, CIITA, HET-E and TP1. It is found in association with other domains, such as the CARD domain (see <PDOC50209>), the DAPIN domain (see <PDOC50824>), the HEAT repeat (see <PDOC50077>), the WD repeat (see <PDOC00574>), the leucine-rich repeat (LRR) or the BIR repeat (see <PDOC00987) [1].

The NACHT domain consists of seven distinct conserved motifs, including the ATP/GTPase specific P-loop (see <PDOC00017>), the Mg(2+)-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 Mg(2+)-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 [1].

Some proteins known to contain a NACHT domain are listed below:

• Mammalian neuronal apoptosis inhibitor protein (NAIP).
• Mammalian MHC class II transcription activator (CIITA).
• Mammalian telomerase-associated protein (TP1).
• Human CARD4 (NOD1), a pro-apoptotic protein, which activate NF-kappaB.
• Streptomyces coelicolor predicted NTPases.
• Synechocystis sp predicted NTPase.
• Podosporina anserina incompatibility locus protein (HET-E).

The profile we developed covers the entire NACHT domain.