Protein Family Models

AAA family ATPase containing an AAA (ATPases Associated with various cellular Activities) domain, may function as an ATP-dependent endonuclease or the ATPase component of an ABC-type transporter

Date:

2024-11-20

This entry represents the topoisomerase-primase (TOPRIM) nucleotidyl transferase/hydrolase domain found in bacterial and archaeal nucleases of the OLD (overcome lysogenization defect) family. The bacteriophage P2 OLD protein, which has DNase as well as RNase activity [1,2] consists of an N-terminal ABC-type ATPase domain and a C-terminal Toprim domain. The nuclease activity of OLD is stimulated by ATP, though the ATPase activity is not DNA-dependent. The TOPRIM domain has two conserved motifs, one of which centres at a conserved glutamate and the other one at two conserved aspartates (DxD). The conserved glutamate may act as a general acid in strand cleavage by nucleases. The DXD motif may co-ordinate Mg2+, a cofactor required for full catalytic function [3]. [1]. 32009148. The full-length structure of Thermus scotoductus OLD defines the ATP hydrolysis properties and catalytic mechanism of Class 1 OLD family nucleases. Schiltz CJ, Adams MC, Chappie JS;. Nucleic Acids Res. 2020;48:2762-2776. [2]. 7836278. The old exonuclease of bacteriophage P2. Myung H, Calendar R;. J Bacteriol. 1995;177:497-501. [3]. 9722641. Toprim--a conserved catalytic domain in type IA and II topoisomerases, DnaG-type primases, OLD family nucleases and RecR proteins. Aravind L, Leipe DD, Koonin EV;. Nucleic Acids Res 1998;26:4205-4213. (from Pfam)

Date:

2024-10-16

Date:

2024-08-14

This family of domains contain a P-loop motif that is characteristic of the AAA superfamily. (from Pfam)

Date:

2024-08-14

Several members are annotated as being of the abortive phage resistance system, in which case the family would be acting as the toxin for a type IV toxin-antitoxin resistance system. (from Pfam)

Date:

2024-08-14

This entry contains YjbD from Escherichia coli (Swiss:P75828), which is annotated as a nucleotide triphosphate hydrolase. (from Pfam)

Date:

2024-08-14

This domain is found at the N terminus of SMC proteins. The SMC (structural maintenance of chromosomes) superfamily proteins have ATP-binding domains at the N- and C-termini, and two extended coiled-coil domains separated by a hinge in the middle. The eukaryotic SMC proteins form two kind of heterodimers: the SMC1/SMC3 and the SMC2/SMC4 types. These heterodimers constitute an essential part of higher order complexes, which are involved in chromatin and DNA dynamics [1]. This family also includes the RecF and RecN proteins that are involved in DNA metabolism and recombination. [1]. 10429180. Structural maintenance of chromosomes (SMC) proteins: conserved molecular properties for multiple biological functions. Strunnikov AV, Jessberger R;. Eur J Biochem 1999;263:6-13. [2]. 9640531. SMC protein complexes and higher-order chromosome dynamics. Hirano T;. Curr Opin Cell Biol 1998;10:317-322. (from Pfam)

Date:

2024-10-16