PDBsum entry 3dd4

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protein metals links
Transport protein PDB id
Protein chain
214 a.a. *
_CA ×2
Waters ×19
* Residue conservation analysis
PDB id:
Name: Transport protein
Title: Structural basis of kchip4a modulation of kv4.3 slow inactiv
Structure: Kv channel-interacting protein 4. Chain: a. Synonym: kchip4, a-type potassium channel modulatory protei potassium channel-interacting protein 4, calsenilin-like pr engineered: yes
Source: Mus musculus. Mouse. Organism_taxid: 10090. Gene: kcnip4, calp, kchip4. Expressed in: escherichia coli. Expression_system_taxid: 562.
3.00Å     R-factor:   0.239     R-free:   0.299
Authors: J.Chai,H.Wang,K.Wang
Key ref: P.Liang et al. (2009). Structural Insights into KChIP4a Modulation of Kv4.3 Inactivation. J Biol Chem, 284, 4960-4967. PubMed id: 19109250
05-Jun-08     Release date:   23-Dec-08    
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Protein chain
Pfam   ArchSchema ?
Q6PHZ8  (KCIP4_MOUSE) -  Kv channel-interacting protein 4
250 a.a.
214 a.a.*
Key:    PfamA domain  Secondary structure
* PDB and UniProt seqs differ at 27 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biochemical function     calcium ion binding     1 term  


J Biol Chem 284:4960-4967 (2009)
PubMed id: 19109250  
Structural Insights into KChIP4a Modulation of Kv4.3 Inactivation.
P.Liang, H.Wang, H.Chen, Y.Cui, L.Gu, J.Chai, K.Wang.
Dynamic inactivation in Kv4 A-type K(+) current plays a critical role in regulating neuronal excitability by shaping action potential waveform and duration. Multifunctional auxiliary KChIP1-4 subunits, which share a high homology in their C-terminal core regions, exhibit distinctive modulation of inactivation and surface expression of pore-forming Kv4 subunits. However, the structural differences that underlie the functional diversity of Kv channel-interacting proteins (KChIPs) remain undetermined. Here we have described the crystal structure of KChIP4a at 3.0A resolution, which shows distinct N-terminal alpha-helices that differentiate it from other KChIPs. Biochemical experiments showed that competitive binding of the Kv4.3 N-terminal peptide to the hydrophobic groove of the core of KChIP4a causes the release of the KChIP4a N terminus that suppresses the inactivation of Kv4.3 channels. Electrophysiology experiments confirmed that the first N-terminal alpha-helix peptide (residues 1-34) of KChIP4a, either by itself or fused to N-terminal truncated Kv4.3, can confer slow inactivation. We propose that N-terminal binding of Kv4.3 to the core of KChIP4a mobilizes the KChIP4a N terminus, which serves as the slow inactivation gate.