This domain is found at the C-terminus of the sporulation regulator WhiA. It is predicted to form a DNA-binding helix-turn-helix structure [2]. The WhiA protein also contains two N-terminal domains that are distant homologues of LAGLIDADG homing endonucleases [2].

1: WhiA, a protein of unknown function conserved among gram-positive bacteria, is essential for sporulation in Streptomyces coelicolor A3(2). Ainsa JA, Ryding NJ, Hartley N, Findlay KC, Bruton CJ, Chater KF; J Bacteriol. 2000;182:5470-5478. PMID:10986251

2: Bacterial DUF199/COG1481 Proteins Including Sporulation Regulator WhiA are Distant Homologs of LAGLIDADG Homing Endonucleases That Retained Only DNA Binding. Knizewski L, Ginalski K; Cell Cycle. 2007;6:1666-1670. PMID:17603302

3: The structure of a bacterial DUF199/WhiA protein: domestication of an invasive endonuclease. Kaiser BK, Clifton MC, Shen BW, Stoddard BL; Structure. 2009;17:1368-1376. PMID:19836336