1XFD

Structure of a human A-type Potassium Channel Accelerating factor DPPX, a member of the dipeptidyl aminopeptidase family

1XFD の概要

• エントリーDOI: 10.2210/pdb1xfd/pdb
• 分子名称: Dipeptidyl aminopeptidase-like protein 6, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, beta-D-mannopyranose-(1-4)-alpha-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-alpha-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (8 entities in total)
• 機能のキーワード: dppx; dpp6; kv4; kv; kaf, membrane protein
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 343739.41

構造登録者

Strop, P.,Bankovich, A.J.,Hansen, K.C.,Garcia, K.C.,Brunger, A.T. (登録日: 2004-09-14, 公開日: 2004-10-26, 最終更新日: 2024-10-09)

主引用文献

Strop, P.,Bankovich, A.J.,Hansen, K.C.,Garcia, K.C.,Brunger, A.T.
Structure of a human A-type potassium channel interacting protein DPPX, a member of the dipeptidyl aminopeptidase family
J.Mol.Biol., 343:1055-1065, 2004

PubMed 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).

PubMed: 15476821
DOI: 10.1016/j.jmb.2004.09.003

実験手法

X-RAY DIFFRACTION (3 Å)