LIS - Legume Information System
Information about legume traits for crop improvement
CicerMine
v5.1.0.3
Cicer data from the Legume Information System
v5.1.0.3
Cicer data from the Legume Information System
| Type | Domain |
| Description | This topoisomerase-primase (TOPRIM) nucleotidyl transferase/hydrolase domain is 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 [ , ], 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. OLD hologues are divided in two classes based on sequence length and the presence/absence of a unique UvrD/PcrA/Rep-like helicase gene immediately downstream in the genome. Despite degenerate conservation in the C-terminal domain between classes, they conserve the catalytic mechanism for DNA cleavage []. Functional details on OLD are scant and further experimentation is required to define the relationship between the ATPase and Toprim nuclease domains, but in vitro studies on P2 OLD suggest that ATPase and nuclease activities are required for OLD function [].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 []. |
| Short Name | TOPRIM_OLD |
