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 | Homologous_superfamily |
| Description | This entry represent a PD-(D/E)XK endonuclease-like domain superfamily [ ]. PD-(D/E)XK nucleases constitute a large and highly diverse superfamily of enzymes that display little sequence similarity. However, they share a common core fold and a few critical active site residues []. This domain can be found at the C terminus of nuclease/helicase AddA, AddB, and RecB.There are two classes of helicase-nuclease complex involved in the initiation step for recombinational repair. AddAB-type enzymes (also called RexAB) are found mainly in Gram-positive bacteria, whereas heterotrimeric RecBCD-type enzymes are found mainly in Gram-negative bacteria [ ]. The RecBCD holoenzyme has a single nuclease domain found in RecB []. Exodeoxyribonuclease V, or RecBCD holoenzyme, is a multifunctional nuclease with potent ATP-dependent exodeoxyribonuclease activity. Ejection of RecD, as occurs at chi recombinational hotspots, cripples exonuclease activity in favor of recombinagenic helicase activity. All proteins in this family for which functions are known are DNA-DNA helicases that are used as part of an exonuclease-helicase complex (made up of RecBCD homologues) that function to generate substrates for the initiation of recombination and recombinational repair. The complex catalyses exonucleolytic cleavage in either the 5' to 3' or 3' to 5' direction to yield 5-phosphooligonucleotides in the presence of ATP [].This superfamily includes phage-type exonucleases ( ) and the C-terminal domain of RecB exodeoxyribonuclease V exonuclease ( ), which are closely related in sequence and structure, containing a restriction enzyme-like core fold. Exonuclease from Bacteriophage lambda facilitates phage DNA recombination through the double-strand break repair (DSBR) and single-strand annealing pathways; it is also important for the late, rolling-circle mode of lambda DNA replication. This magnesium-dependent enzyme catalyses the exonucleolytic cleavage of DNA in the 5'- to 3'-direction to yield nucleoside 5'-phosphates. Lambda exonuclease is a trimer of three subunits that form a toroid structure with a tapered channel passing through the middle [ ]. |
| Short Name | PDDEXK-like_dom_sf |
