1XFD
Structure of a human A-type Potassium Channel Accelerating factor DPPX, a member of the dipeptidyl aminopeptidase family
Summary for 1XFD
| Entry DOI | 10.2210/pdb1xfd/pdb |
| Descriptor | 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) |
| Functional Keywords | dppx; dpp6; kv4; kv; kaf, membrane protein |
| Biological source | Homo sapiens (human) |
| Total number of polymer chains | 4 |
| Total formula weight | 343739.41 |
| Authors | Strop, P.,Bankovich, A.J.,Hansen, K.C.,Garcia, K.C.,Brunger, A.T. (deposition date: 2004-09-14, release date: 2004-10-26, Last modification date: 2024-10-09) |
| Primary citation | 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 Cited by 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: 15476821DOI: 10.1016/j.jmb.2004.09.003 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (3 Å) |
Structure validation
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