1xfd: Difference between revisions

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[[Image:1xfd.gif|left|200px]]<br /><applet load="1xfd" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1xfd.gif|left|200px]]<br /><applet load="1xfd" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1xfd, resolution 3.00Å" />

'''Structure of a human A-type Potassium Channel Accelerating factor DPPX, a member of the dipeptidyl aminopeptidase family'''<br />

==Overview==

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).

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).

==About this Structure==

1XFD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1XFD OCA].

1XFD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XFD OCA].

==Reference==

Line 13:

[[Category: Homo sapiens]]

[[Category: Single protein]]

[[Category: Bankovich, A.J.]]

[[Category: Bankovich, A J.]]

[[Category: Brunger, A.T.]]

[[Category: Brunger, A T.]]

[[Category: Garcia, K.C.]]

[[Category: Garcia, K C.]]

[[Category: Hansen, K.C.]]

[[Category: Hansen, K C.]]

[[Category: Strop, P.]]

[[Category: dppx; dpp6; kv4; kv; kaf]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Wed Nov~~ 21 06:02:~~25 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:54:10 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1xfd.gif|left|200px]]<br /><applet load="1xfd" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1xfd.gif|left|200px]]<br /><applet load="1xfd" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1xfd, resolution 3.00&Aring;" />
 '''Structure of a human A-type Potassium Channel Accelerating factor DPPX, a member of the dipeptidyl aminopeptidase family'''<br />
 ==Overview==
-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).
+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).
 ==About this Structure==
-XFD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1XFD OCA].
+XFD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XFD OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Homo sapiens]]
 [[Category: Single protein]]
-[[Category: Bankovich, A.J.]]
+[[Category: Bankovich, A J.]]
-[[Category: Brunger, A.T.]]
+[[Category: Brunger, A T.]]
-[[Category: Garcia, K.C.]]
+[[Category: Garcia, K C.]]
-[[Category: Hansen, K.C.]]
+[[Category: Hansen, K C.]]
 [[Category: Strop, P.]]
 [[Category: dppx; dpp6; kv4; kv; kaf]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 06:02:25 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:54:10 2008''