eIF5A, previously thought to be an initiation factor, has been shown to be required for peptide chain elongation in yeast .
A five-stranded beta-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 beta-sheet coiled to form a closed beta-barrel capped by an alpha 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].
Peat TS, Newman J, Waldo GS, Berendzen J, Terwilliger TC; , Structure 1998;6:1207-1214.: Structure of translation initiation factor 5A from Pyrobaculum aerophilum at 1.75 A resolution. PUBMED:9753699 EPMC:9753699 .