| Type: | Domain | Name: | K Homology domain, type 2 |
| Description: | The K homology (KH) domain was first identified in the human heterogeneous nuclear ribonucleoprotein (hnRNP) K. It is a domain of around 70 amino acidsthat is present in a wide variety of quite diverse nucleic acid-binding proteins []. It has been shown to bind RNA [, ]. Like many other RNA-binding motifs, KH motifs are found in one or multiple copies (14 copies in chicken vigilin) and, at least for hnRNP K (three copies) and FMR-1 (two copies), each motif is necessary for in vitroRNA binding activity, suggesting that they may function cooperatively or, in the case of single KH motif proteins (for example, Mer1p), independently [].According to structural analyses [, , ], the KH domain can be separated in two groups. The first group or type-1 contain a beta-alpha-alpha-beta-beta-alpha structure, whereas in the type-2 the two last beta-sheets are located in the N-terminal part of the domain (alpha-beta-beta-alpha-alpha-beta). Sequence similarity between these two folds are limited to a short region (VIGXXGXXI) in the RNA binding motif. This motif is located between helice 1 and 2 in type-1 and between helice 2 and 3 in type-2. Proteins known to contain a type-2 KH domain include eukaryotic and prokaryotic S3 family of ribosomal proteins, and the prokaryotic GTP-binding protein era. | Short Name: | KH_dom_type_2 |
| DB identifier | Type | Name |
|---|---|---|
| IPR009019 | Domain | K homology domain, prokaryotic type |
| IPR005662 | Family | GTP-binding protein Era |
| IPR015946 | Domain | K homology domain-like, alpha/beta |
| IPR005704 | Family | Ribosomal protein S3, bacterial |
| IPR005703 | Family | Ribosomal protein S3, eukaryotic/archaeal |
| IPR010212 | Family | Probable transcription termination protein NusA, archaeal |
