KH domain

Quality 0.50 · 0 views · Updated 2 months ago

title: "KH domain" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["protein-domains", "protein-superfamilies"] topic_path: "general/protein-domains" source: "https://en.wikipedia.org/wiki/KH_domain" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::data[format=table title="Infobox protein family"]

Field	Value
Symbol	KH_1
Name	KH domain
image	PDB_2anr_EBI.png
caption	Structure of a KH domain from the human protein vigilin.
Pfam	PF00013
Pfam_clan	CL0007
ECOD	327.11.2
InterPro	IPR004088
SMART	KH
SCOP	1vig
PDB	, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
::

::callout[type=note] the protein ::

Nucleic acid binding

KH domains bind to either RNA or single stranded DNA. The nucleic acid is bound in an extended conformation across one side of the domain. The binding occurs in a cleft formed between alpha helix 1, alpha helix 2 the GXXG loop (contains a highly conserved sequence motif) and the variable loop. The binding cleft is hydrophobic in nature with a variety of additional protein specific interactions to stabilise the complex. Valverde and colleagues note that, "Nucleic acid base-to-protein aromatic side chain stacking interactions which are prevalent in other types of single stranded nucleic acid binding motifs, are notably absent in KH domain nucleic acid recognition".

Structural groups

::figure[src="https://upload.wikimedia.org/wikipedia/commons/7/7e/KH_fold_types.png" caption="The two types of KH domain."] ::

Structurally there are two different types of KH domains identified by Grishin which are called type I and type II. The type I domains are mainly found in eukaryotic proteins, while the type II domains are predominantly found in prokaryotes. While both types share a minimal consensus sequence motif they have different structural folds. The type I KH domains have a three stranded beta-sheet where all three strands are anti-parallel. In the type II domain two of the three beta strands are in a parallel orientation. While type I domains are usually found in multiple copies within proteins, the type II are typically found in a single copy per protein.

Human proteins containing this domain

AKAP1; ANKHD1; ANKRD17; ASCC1; BICC1; DDX43; DDX53; DPPA5; ERAL1; FMR1; FUBP1; FUBP3; FXR1; FXR2; GLD1; HDLBP; HNRPK; IGF2BP1; IGF2BP2; IGF2BP3; KHDRBS1; KHDRBS2; KHDRBS3; KHSRP; KRR1; MEX3A; MEX3B; MEX3C; MEX3D; NOVA1; NOVA2; PCBP1; PCBP2; PCBP3; PCBP4; PNO1; PNPT1; QKI; SF1; TDRKH;

References

(April 2007). "The structure of the C-terminal KH domains of KSRP reveals a noncanonical motif important for mRNA degradation". Structure.
(September 1997). "The solution structure of the first KH domain of FMR1, the protein responsible for the fragile X syndrome". Nat. Struct. Biol..
(June 1999). "High precision solution structure of the C-terminal KH domain of heterogeneous nuclear ribonucleoprotein K, a c-myc transcription factor". J. Mol. Biol..
Grishin NV. (February 2001). "KH domain: one motif, two folds". Nucleic Acids Res..
(June 2008). "Structure and function of KH domains". FEBS J..

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::