Lineage for Family a.4.1.20: RpiR-like

1. Root: SCOPe 2.08

2. Class a: All alpha proteins [46456] (290 folds)

3. Fold a.4: DNA/RNA-binding 3-helical bundle [46688] (14 superfamilies) core: 3-helices; bundle, closed or partly opened, right-handed twist; up-and down

4. Superfamily a.4.1: Homeodomain-like [46689] (21 families) consists only of helices

5. Family a.4.1.20: RpiR-like [158263] (1 protein) Pfam PF01418; contains two extra helices, one at each termini; overall arrangment of five helices is similar to the helical core of the lambda integrase-like catalytic domain (56350)