A five-stranded β-barrel was first noted as a common structure among four proteins binding single-stranded nucleic acids (staphylococcal nuclease and aspartyl-tRNA synthetase) or oligosaccharides (B subunits of enterotoxin and verotoxin-1), and has been termed the oligonucleotide/oligosaccharide binding motif, or OB fold, a five-stranded β-sheet coiled to form a closed β-barrel capped by an α … expand

A five-stranded β-barrel was first noted as a common structure among four proteins binding single-stranded nucleic acids (staphylococcal nuclease and aspartyl-tRNA synthetase) or oligosaccharides (B subunits of enterotoxin and verotoxin-1), and has been termed the oligonucleotide/oligosaccharide binding motif, or OB fold, a five-stranded β-sheet coiled to form a closed β-barrel capped by an α helix located between the third and fourth strands [ PUBMED:12769718 ]. Two ribosomal proteins, S17 and S1, are members of this class, and have different variations of the OB fold theme. Comparisons with other OB fold nucleic acid binding proteins suggest somewhat different mechanisms of nucleic acid recognition in each case [ PUBMED:9862955 ].

There are many nucleic acid-binding proteins that contain domains with this OB-fold structure, including anticodon-binding tRNA synthetases, ssDNA-binding proteins (CDC13, telomere-end binding proteins), phage ssDNA-binding proteins (gp32, gp2.5, gpV), cold shock proteins, DNA ligases, RNA-capping enzymes, DNA replication initiators and RNA polymerase subunit RBP8 [ PUBMED:15178340 ].

This entry represents the RNA-binding domain of translation elongation factor IF5A [ PUBMED:19424157 ].