The K homology domain is a common RNA-binding motif present in one or multiple copies in both prokaryotic and eukaryotic regulatory proteins. These motifs may act cooperatively to bind RNA in the case of multiple motifs, or independently in the case of single KH motif proteins. The structure of the prokaryotic KH domain consists of a two-layer alpha/beta fold in the arrangement alpha/beta(2)/alpha/beta. This entry represents the KH domain from RNA-binding protein KhpA and KhpB (also known as Jag or EloR) [1]. KhpA is a single-KH domain protein while KhpB also has a Jag-N domain (Pfam:PF14804) of unknown function and a R3H domain (Pfam:PF01424) at the C-terminal [1].

1: Absence of the KhpA and KhpB (JAG/EloR) RNA-binding proteins suppresses the requirement for PBP2b by overproduction of FtsA in Streptococcus pneumoniae D39. Zheng JJ, Perez AJ, Tsui HT, Massidda O, Winkler ME; Mol Microbiol. 2017;106:793-814. PMID:28941257