K Homology domain, type 1 superfamily
IPR036612
Definition
The K homology (KH) domain was first identified in the human heterogeneous nuclear ribonucleoprotein (hnRNP) K. It is a domain of around 70 amino acids that is present in a wide variety of quite diverse nucleic acid-binding proteins PMID:8036511. It has been shown to bind RNA [[cite:PMID:9302998], [cite:PMID:10369774]]. 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 forin vitroRNA binding activity, suggesting that they may function cooperatively or, in the case of single KH motif proteins (for example, Mer1p), independently PMID:8036511. According to structural [[cite:PMID:9302998], [cite:PMID:10369774], [cite:PMID:11160884]] analysis the KH domain can be separated in two groups. The first group or type-1 contain a β-α-α-β-β-α structure, whereas in the type-2 the two last β-sheet are located in the N-terminal part of the domain (α-β-β-α-α-β). Sequence similarity between these two folds are limited to a short region (VIGXXGXXI) in the RNA binding motif. This motif is located between helices 1 and 2 in type-1 and between helices 2 and 3 in type-2. Proteins known to contain a type-1 KH domain include bacterial polyribonucleotide nucleotidyltransferase ([ec:2.7.7.8]); vertebrate Fragile X messenger ribonucleoprotein 1 (FMR1); eukaryotic heterogeneous nuclear ribonucleoprotein K (hnRNP K), one of at least 20 major proteins that are part of hnRNP particles in mammalian cells; mammalian poly(rC) binding proteins; Artemia salina glycine-rich protein GRP33; yeast PAB1-binding protein 2 (PBP2); vertebrate vigilin; and human high-density lipoprotein binding protein (HDL-binding protein).
46 human proteins with this domain
Each is a reviewed human protein in the Seroatlas serome and a potential autoantibody target; this domain groups them into one antibody-relevant category. Every entry links to its own record.
Loading the interactive Seroatlas explorer...