Strop_2004_J.Mol.Biol_343_1055

Reference

Title : Structure of a human A-type potassium channel interacting protein DPPX, a member of the dipeptidyl aminopeptidase family - Strop_2004_J.Mol.Biol_343_1055
Author(s) : Strop P , Bankovich AJ , Hansen KC , Garcia KC , Brunger AT
Ref : Journal of Molecular Biology , 343 :1055 , 2004
Abstract :

It has recently been reported that dipeptidyl aminopeptidase X (DPPX) interacts with the voltage-gated potassium channel Kv4 and that co-expression of DPPX together with Kv4 pore forming alpha-subunits, and potassium channel interacting proteins (KChIPs), reconstitutes properties of native A-type potassium channels in vitro. Here we report the X-ray crystal structure of the extracellular domain of human DPPX determined at 3.0A resolution. This structure reveals the potential for a surface electrostatic change based on the protonation state of histidine. Subtle changes in extracellular pH might modulate the interaction of DPPX with Kv4.2 and possibly with other proteins. We propose models of DPPX interaction with the voltage-gated potassium channel complex. The dimeric structure of DPPX is highly homologous to the related protein DPP-IV. Comparison of the active sites of DPPX and DPP-IV reveals loss of the catalytic serine residue but the presence of an additional serine near the "active" site. However, the arrangement of residues is inconsistent with that of canonical serine proteases and DPPX is unlikely to function as a protease (dipeptidyl aminopeptidase).

PubMedSearch : Strop_2004_J.Mol.Biol_343_1055
PubMedID: 15476821
Gene_locus related to this paper: human-DPP6

Related information

Gene_locus human-DPP6
Structure human-DPP6    1XFD

Citations formats

Strop P, Bankovich AJ, Hansen KC, Garcia KC, Brunger AT (2004)
Structure of a human A-type potassium channel interacting protein DPPX, a member of the dipeptidyl aminopeptidase family
Journal of Molecular Biology 343 :1055

Strop P, Bankovich AJ, Hansen KC, Garcia KC, Brunger AT (2004)
Journal of Molecular Biology 343 :1055