The KH-like domain at the C-terminus of the EngA subfamily of essential bacterial GTPases has a unique domain structure position. The two adjacent GTPase domains (GD1 and GD2), two domains of family MMR_HSR1, Pfam:PF01926, pack at either side of the C-terminal domain. This C-terminal domain resembles a KH domain but is missing the distinctive RNA recognition elements. Conserved motifs of the nucleotide binding site of GD1 are integral parts of the GD1-KH domain interface, suggesting the interactions between these two domains are directly influenced by the GTP/GDP cycling of the protein. In contrast, the GD2-KH domain interface is distal to the GDP binding site of GD2. This family has not been added to the KH clan since SCOP classifies it separately due to its missing the key KH motif/fold.

1: Domain arrangement of Der, a switch protein containing two GTPase domains. Robinson VL, Hwang J, Fox E, Inouye M, Stock AM; Structure. 2002;10:1649-1658. PMID:12467572