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 | Family |
| Description | Members of this group contain the Toprim domain (topoisomerase-primase) common to DnaG primases, type IA and type II topoisomerases, OLD family nucleases, as well as small primase-like proteins from bacteria and archaea, and bacterial DNA repair proteins of the RecR/M family [ ].The domain consists of approximately 100 amino acids and have two conserved motifs, one of which centres at a conserved glutamate and the other one at two conserved aspartates (DxD). Examination of the structure of Topo IA and Topo II and modelling of the Toprim domains of the primases reveal a compact beta/alpha fold, with the conserved negatively charged residues juxtaposed, and inserts seen in Topo IA and Topo II [ ]. The conserved glutamate may act as a general base in nucleotide polymerisation by primases and in strand rejoining by topoisomerases and as a general acid in strand cleavage by topoisomerases and nucleases. The role of this glutamate in catalysis is supported by site-directed mutagenesis data on primases and Topo IA []. The DxD motif may coordinate Mg2+that is required for the activity of all Toprim-containing enzymes. The common ancestor could encode a prototype Toprim enzyme that might have had both nucleotidyl transferase and polynucleotide cleaving activity [ ].There is currently no experimental data for members of this group. As they lack the additional domains that are involved in numerous interactions typical of the larger proteins of the Toprim superfamily (primases and topoisomerases), they may represent a novel class of nucleotidyl transferases or nucleases [ ]. |
| Short Name | UCP016662_toprim |
