KH

K homology RNA-binding domain
KH
SMART accession number:SM00322
Description: -
Interpro abstract (IPR004087):

The K homology (KH) domain was first identified in the human heterogeneous nuclear ribonucleoprotein (hnRNP) K. An evolutionarily conserved sequence of around 70 amino acids, the KH domain is present in a wide variety of nucleic acid-binding proteins. The KH domain binds RNA, and can function in RNA recognition [(PUBMED:17437720)]. It is found in multiple copies in several proteins, where they can function cooperatively or independently. For example, in the AU-rich element RNA-binding protein KSRP, which has 4 KH domains, KH domains 3 and 4 behave as independent binding modules to interact with different regions of the AU-rich RNA targets [(PUBMED:17437720)]. The solution structure of the first KH domain of FMR1 [(PUBMED:9302998)] and of the C-terminal KH domain of hnRNP K [(PUBMED:10369774)] determined by nuclear magnetic resonance (NMR) revealed a beta-alpha-alpha-beta-beta-alpha structure. Proteins containing KH domains include:

  • Bacterial and organelle PNPases [(PUBMED:17337072)].
  • Archaeal and eukaryotic exosome subunits [(PUBMED:17159918)].
  • Eukaryotic and prokaryotic RS3 ribosomal proteins [(PUBMED:1160884)].
  • Vertebrate fragile X mental retardation protein 1 (FMR1) [(PUBMED:15805463)].
  • Vigilin, which has 14 KH domains [(PUBMED:14618268)].
  • AU-rich element RNA-binding protein KSRP.
  • hnRNP K, which contains 3 KH domains.
  • Human onconeural ventral antigen-1 (NOVA-1) [(PUBMED:10368286)].

According to structural analyses [(PUBMED:9302998), (PUBMED:10369774), (PUBMED:11160884)], the KH domain can be separated in two groups - type 1 and type 2.

GO function:nucleic acid binding (GO:0003676)
Family alignment:
View or

There are 51257 KH domains in 32523 proteins in SMART's nrdb database.

Click on the following links for more information.