Comparison of the ERA C-terminal RNA-binding domain (Chen, Court, and Ji. Proc. Natl. Acad. Sci. USA 1999; 96:8396-410. Abstract) with the Nova-KH·ssRNA complex (Lewis, Musunuru, Jensen, Edo, Chen, Darnell, and Burley. Cell 2000; 100:323-32). HLH stands for the helix-loop-helix motif and VL for the variable loop. Both HLH and VL are RNA-interacting motifs of the KH domains.