InterPro: IPR004365 Nucleic acid binding, OB-fold, tRNA/helicase-type

The OB-fold (oligonucleotide/oligosaccharide-binding fold) is found in all three kingdoms and its common architecture presents a binding face that has adapted to bind different ligands. The OB-fold is a five/six-stranded closed beta-barrel formed by 70-80 amino acid residues. The strands are connected by loops of varying length which form the functional appendages of the protein. The majority of OB-fold proteins use the same face for ligand binding or as an active site. Different OB-fold proteins use this 'fold-related binding face' to, variously, bind oligosaccharides, oligonucleotides, proteins, metal ions and catalytic substrates.

This entry contains OB-fold domains that bind to nucleic acids [1]. It includes the anti-codon binding domain of lysyl, aspartyl, and asparaginyl-tRNA synthetases (See IPR004364). Aminoacyl-tRNA synthetases catalyse the addition of an amino acid to the appropriate tRNA molecule EC:6.1.1. This domain is found in RecG helicase involved in DNA repair. Replication factor A is a heterotrimeric complex, that contains a subunit in this family [2, 3]. This domain is also found at the C terminus of bacterial DNA polymerase III alpha chain.