InterPro domain: IPR014721

Domain 2 of the ribosomal protein S5 has a left-handed beta-alpha-beta fold that is found in numerous RNA/DNA-binding proteins, as well as in kinases from the GHMP kinase family. Proteins containing this beta-alpha-beta fold domain include:

• Translational machinery components (ribosomal proteins S5 and S9, and domain IV of elongation factors EF-G and eEF-2) [ 1 ].
• Ribonuclease P protein (RNase P) [ 2 ].
• DNA modification proteins (DNA mismatch repair proteins MutL and PMS2, DNA gyrase B, DNA topoisomerase II, IV-B and VI-B) [ 3 ].
• GHMP kinases that transfer a phosphoryl group from ATP to an acceptor (galactokinase ( 2.7.1.6 ), homoserine kinase ( 2.7.1.39 ), and mevalonate kinase ( 2.7.1.36 )) [ 4 , 5 ].
• Caenorhabditis elegans early switch protein Xol-1 (a divergent member of the GHMP kinase family that has lost the ATP-binding site) [ 6 ].

1. Structures of prokaryotic ribosomal proteins: implications for RNA binding and evolution. Biochem. Cell Biol. 73, 979-86
2. Structure and function of eukaryotic Ribonuclease P RNA. Mol. Cell 24, 445-56
3. Structure and function of the N-terminal 40 kDa fragment of human PMS2: a monomeric GHL ATPase. EMBO J. 20, 5521-31
4. Molecular functions of conserved aspects of the GHMP kinase family. Biochemistry 43, 14594-601
5. Structure and mechanism of homoserine kinase: prototype for the GHMP kinase superfamily. Structure 8, 1247-57
6. XOL-1, primary determinant of sexual fate in C. elegans, is a GHMP kinase family member and a structural prototype for a class of developmental regulators. Genes Dev. 17, 977-90