1qyc: Difference between revisions

Revision as of 15:45, 21 February 2008

Crystal structures of pinoresinol-lariciresinol and phenylcoumaran benzylic ether reductases, and their relationship to isoflavone reductases

OverviewOverview

Despite the importance of plant lignans and isoflavonoids in human health protection (e.g. for both treatment and prevention of onset of various cancers) as well as in plant biology (e.g. in defense functions and in heartwood development), systematic studies on the enzymes involved in their biosynthesis have only recently begun. In this investigation, three NADPH-dependent aromatic alcohol reductases were comprehensively studied, namely pinoresinol-lariciresinol reductase (PLR), phenylcoumaran benzylic ether reductase (PCBER), and isoflavone reductase (IFR), which are involved in central steps to the various important bioactive lignans and isoflavonoids. Of particular interest was in determining how differing regio- and enantiospecificities are achieved with the different enzymes, despite each apparently going through similar enone intermediates. Initially, the three-dimensional x-ray crystal structures of both PLR_Tp1 and PCBER_Pt1 were solved and refined to 2.5 and 2.2 A resolutions, respectively. Not only do they share high gene sequence similarity, but their structures are similar, having a continuous alpha/beta NADPH-binding domain and a smaller substrate-binding domain. IFR (whose crystal structure is not yet obtained) was also compared (modeled) with PLR and PCBER and was deduced to have the same overall basic structure. The basis for the distinct enantio-specific and regio-specific reactions of PCBER, PLR, and IFR, as well as the reaction mechanism and participating residues involved (as identified by site-directed mutagenesis), are discussed.

About this StructureAbout this Structure

1QYC is a Single protein structure of sequence from Pinus taeda. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structures of pinoresinol-lariciresinol and phenylcoumaran benzylic ether reductases and their relationship to isoflavone reductases., Min T, Kasahara H, Bedgar DL, Youn B, Lawrence PK, Gang DR, Halls SC, Park H, Hilsenbeck JL, Davin LB, Lewis NG, Kang C, J Biol Chem. 2003 Dec 12;278(50):50714-23. Epub 2003 Sep 16. PMID:13129921

Page seeded by OCA on Thu Feb 21 14:45:02 2008

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

OCA

@@ Line 1: / Line 1: @@
-[[Image:1qyc.gif|left|200px]]<br /><applet load="1qyc" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1qyc.gif|left|200px]]<br /><applet load="1qyc" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1qyc, resolution 2.2&Aring;" />
 '''Crystal structures of pinoresinol-lariciresinol and phenylcoumaran benzylic ether reductases, and their relationship to isoflavone reductases'''<br />
 ==Overview==
-Despite the importance of plant lignans and isoflavonoids in human health, protection (e.g. for both treatment and prevention of onset of various, cancers) as well as in plant biology (e.g. in defense functions and in, heartwood development), systematic studies on the enzymes involved in, their biosynthesis have only recently begun. In this investigation, three, NADPH-dependent aromatic alcohol reductases were comprehensively studied, namely pinoresinol-lariciresinol reductase (PLR), phenylcoumaran benzylic, ether reductase (PCBER), and isoflavone reductase (IFR), which are, involved in central steps to the various important bioactive lignans and, isoflavonoids. Of particular interest was in determining how differing, regio- and enantiospecificities are achieved with the different enzymes, despite each apparently going through similar enone intermediates., Initially, the three-dimensional x-ray crystal structures of both PLR_Tp1, and PCBER_Pt1 were solved and refined to 2.5 and 2.2 A resolutions, respectively. Not only do they share high gene sequence similarity, but, their structures are similar, having a continuous alpha/beta NADPH-binding, domain and a smaller substrate-binding domain. IFR (whose crystal, structure is not yet obtained) was also compared (modeled) with PLR and, PCBER and was deduced to have the same overall basic structure. The basis, for the distinct enantio-specific and regio-specific reactions of PCBER, PLR, and IFR, as well as the reaction mechanism and participating residues, involved (as identified by site-directed mutagenesis), are discussed.
+Despite the importance of plant lignans and isoflavonoids in human health protection (e.g. for both treatment and prevention of onset of various cancers) as well as in plant biology (e.g. in defense functions and in heartwood development), systematic studies on the enzymes involved in their biosynthesis have only recently begun. In this investigation, three NADPH-dependent aromatic alcohol reductases were comprehensively studied, namely pinoresinol-lariciresinol reductase (PLR), phenylcoumaran benzylic ether reductase (PCBER), and isoflavone reductase (IFR), which are involved in central steps to the various important bioactive lignans and isoflavonoids. Of particular interest was in determining how differing regio- and enantiospecificities are achieved with the different enzymes, despite each apparently going through similar enone intermediates. Initially, the three-dimensional x-ray crystal structures of both PLR_Tp1 and PCBER_Pt1 were solved and refined to 2.5 and 2.2 A resolutions, respectively. Not only do they share high gene sequence similarity, but their structures are similar, having a continuous alpha/beta NADPH-binding domain and a smaller substrate-binding domain. IFR (whose crystal structure is not yet obtained) was also compared (modeled) with PLR and PCBER and was deduced to have the same overall basic structure. The basis for the distinct enantio-specific and regio-specific reactions of PCBER, PLR, and IFR, as well as the reaction mechanism and participating residues involved (as identified by site-directed mutagenesis), are discussed.
 ==About this Structure==
-QYC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pinus_taeda Pinus taeda]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1QYC OCA].
+QYC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pinus_taeda Pinus taeda]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QYC OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Pinus taeda]]
 [[Category: Single protein]]
-[[Category: Bedgar, D.L.]]
+[[Category: Bedgar, D L.]]
-[[Category: Davin, L.B.]]
+[[Category: Davin, L B.]]
-[[Category: Gang, D.R.]]
+[[Category: Gang, D R.]]
-[[Category: Halls, S.C.]]
+[[Category: Halls, S C.]]
-[[Category: Hilsenbeck, J.L.]]
+[[Category: Hilsenbeck, J L.]]
 [[Category: Kang, C.]]
 [[Category: Kasahara, H.]]
-[[Category: Lawrence, P.K.]]
+[[Category: Lawrence, P K.]]
 [[Category: Min, T.]]
 [[Category: Park, H.]]
@@ Line 31: / Line 31: @@
 [[Category: plr]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sat Nov 24 21:46:32 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:45:02 2008''