1jdr: Difference between revisions

Revision as of 14:21, 21 February 2008

Crystal Structure of a Proximal Domain Potassium Binding Variant of Cytochrome c Peroxidase

OverviewOverview

Earlier work [Bonagura et al. (1996) Biochemistry 35, 6107] showed that the K+ site found in the proximal pocket of ascorbate peroxidase (APX) could be engineered into cytochrome c peroxidase (CCP). Binding of K+ at the engineered site results in a loss in activity and destabilization of the CCP compound I Trp191 cationic radical owing to long-range electrostatic effects. The engineered CCP mutant crystal structure has been refined to 1.5 A using data obtained at cryogenic temperatures which provides a more detailed basis for comparison with the naturally occurring K+ site in APX. The characteristic EPR signal associated with the Trp191 radical becomes progressively weaker as K+ is added, which correlates well with the loss in enzyme activity as [K+] is increased. These results coupled with stopped-flow studies support our earlier conclusions that the loss in activity and EPR signal is due to destabilization of the Trp191 cationic radical.

About this StructureAbout this Structure

1JDR is a Single protein structure of sequence from Saccharomyces cerevisiae with and as ligands. Active as Cytochrome-c peroxidase, with EC number 1.11.1.5 Full crystallographic information is available from OCA.

ReferenceReference

The effects of an engineered cation site on the structure, activity, and EPR properties of cytochrome c peroxidase., Bonagura CA, Sundaramoorthy M, Bhaskar B, Poulos TL, Biochemistry. 1999 Apr 27;38(17):5538-45. PMID:10220341

Page seeded by OCA on Thu Feb 21 13:21:31 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
-[[Image:1jdr.jpg|left|200px]]<br /><applet load="1jdr" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1jdr.jpg|left|200px]]<br /><applet load="1jdr" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1jdr, resolution 1.5&Aring;" />
 '''Crystal Structure of a Proximal Domain Potassium Binding Variant of Cytochrome c Peroxidase'''<br />
 ==Overview==
-Earlier work [Bonagura et al. (1996) Biochemistry 35, 6107] showed that, the K+ site found in the proximal pocket of ascorbate peroxidase (APX), could be engineered into cytochrome c peroxidase (CCP). Binding of K+ at, the engineered site results in a loss in activity and destabilization of, the CCP compound I Trp191 cationic radical owing to long-range, electrostatic effects. The engineered CCP mutant crystal structure has, been refined to 1.5 A using data obtained at cryogenic temperatures which, provides a more detailed basis for comparison with the naturally occurring, K+ site in APX. The characteristic EPR signal associated with the Trp191, radical becomes progressively weaker as K+ is added, which correlates well, with the loss in enzyme activity as [K+] is increased. These results, coupled with stopped-flow studies support our earlier conclusions that the, loss in activity and EPR signal is due to destabilization of the Trp191, cationic radical.
+Earlier work [Bonagura et al. (1996) Biochemistry 35, 6107] showed that the K+ site found in the proximal pocket of ascorbate peroxidase (APX) could be engineered into cytochrome c peroxidase (CCP). Binding of K+ at the engineered site results in a loss in activity and destabilization of the CCP compound I Trp191 cationic radical owing to long-range electrostatic effects. The engineered CCP mutant crystal structure has been refined to 1.5 A using data obtained at cryogenic temperatures which provides a more detailed basis for comparison with the naturally occurring K+ site in APX. The characteristic EPR signal associated with the Trp191 radical becomes progressively weaker as K+ is added, which correlates well with the loss in enzyme activity as [K+] is increased. These results coupled with stopped-flow studies support our earlier conclusions that the loss in activity and EPR signal is due to destabilization of the Trp191 cationic radical.
 ==About this Structure==
-JDR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with K and HEM as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cytochrome-c_peroxidase Cytochrome-c peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.5 1.11.1.5] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1JDR OCA].
+JDR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=K:'>K</scene> and <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cytochrome-c_peroxidase Cytochrome-c peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.5 1.11.1.5] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JDR OCA].
 ==Reference==
@@ Line 15: / Line 15: @@
 [[Category: Single protein]]
 [[Category: Bhaskar, B.]]
-[[Category: Bonagura, C.A.]]
+[[Category: Bonagura, C A.]]
-[[Category: Poulos, T.L.]]
+[[Category: Poulos, T L.]]
 [[Category: Sundaramoorthy, M.]]
 [[Category: HEM]]
@@ Line 22: / Line 22: @@
 [[Category: helical bundle protein]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 18:08:43 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:21:31 2008''