2fzm
From Proteopedia
(New page: 200px<br /><applet load="2fzm" size="450" color="white" frame="true" align="right" spinBox="true" caption="2fzm, resolution 2.300Å" /> '''Structure of the E....) |
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| - | [[Image:2fzm.jpg|left|200px]]<br /><applet load="2fzm" size=" | + | [[Image:2fzm.jpg|left|200px]]<br /><applet load="2fzm" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2fzm, resolution 2.300Å" /> | caption="2fzm, resolution 2.300Å" /> | ||
'''Structure of the E. coli PutA proline dehydrogenase domain reduced by dithionite and complexed with SO2'''<br /> | '''Structure of the E. coli PutA proline dehydrogenase domain reduced by dithionite and complexed with SO2'''<br /> | ||
==Overview== | ==Overview== | ||
| - | PutA is a novel flavoprotein in Escherichia coli that switches from a | + | PutA is a novel flavoprotein in Escherichia coli that switches from a transcriptional repressor to a membrane-bound proline catabolic enzyme. Previous crystallographic studies of the PutA proline dehydrogenase (PRODH) domain under oxidizing conditions revealed that FAD N(5) and the ribityl 2'-OH group form hydrogen bonds with Arg431 and Arg556, respectively. Here we identify molecular interactions in the PutA PRODH active site that underlie redox-dependent functional switching of PutA. We report that reduction of the PRODH domain induces major structural changes in the FAD cofactor, including a 22 degrees bend of the isoalloxazine ring along the N(5)-N(10) axis, crankshaft rotation of the upper part of the ribityl chain, and formation of a new hydrogen bond network involving the ribityl 2'-OH group, FAD N(1), and Gly435. The roles of the FAD 2'-OH group and the FAD N(5)-Arg431 hydrogen bond pair in regulating redox-dependent PutA-membrane associations were tested using FAD analogues and site-directed mutagenesis. Kinetic membrane binding measurements and cell-based reporter gene assays of modified PutA proteins show that disrupting the FAD N(5)-Arg431 interaction impairs the reductive activation of PutA-membrane binding. We also show that the FAD 2'-OH group acts as a redox-sensitive toggle switch that controls PutA-membrane binding. These results illustrate a new versatility of the ribityl chain in flavoprotein mechanisms. |
==About this Structure== | ==About this Structure== | ||
| - | 2FZM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with FAD and SO2 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Proline_dehydrogenase Proline dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.5.99.8 1.5.99.8] Full crystallographic information is available from [http:// | + | 2FZM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=FAD:'>FAD</scene> and <scene name='pdbligand=SO2:'>SO2</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Proline_dehydrogenase Proline dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.5.99.8 1.5.99.8] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FZM OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Proline dehydrogenase]] | [[Category: Proline dehydrogenase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Tanner, J | + | [[Category: Tanner, J J.]] |
[[Category: FAD]] | [[Category: FAD]] | ||
[[Category: SO2]] | [[Category: SO2]] | ||
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[[Category: puta]] | [[Category: puta]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:26:44 2008'' |
Revision as of 15:26, 21 February 2008
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Structure of the E. coli PutA proline dehydrogenase domain reduced by dithionite and complexed with SO2
Overview
PutA is a novel flavoprotein in Escherichia coli that switches from a transcriptional repressor to a membrane-bound proline catabolic enzyme. Previous crystallographic studies of the PutA proline dehydrogenase (PRODH) domain under oxidizing conditions revealed that FAD N(5) and the ribityl 2'-OH group form hydrogen bonds with Arg431 and Arg556, respectively. Here we identify molecular interactions in the PutA PRODH active site that underlie redox-dependent functional switching of PutA. We report that reduction of the PRODH domain induces major structural changes in the FAD cofactor, including a 22 degrees bend of the isoalloxazine ring along the N(5)-N(10) axis, crankshaft rotation of the upper part of the ribityl chain, and formation of a new hydrogen bond network involving the ribityl 2'-OH group, FAD N(1), and Gly435. The roles of the FAD 2'-OH group and the FAD N(5)-Arg431 hydrogen bond pair in regulating redox-dependent PutA-membrane associations were tested using FAD analogues and site-directed mutagenesis. Kinetic membrane binding measurements and cell-based reporter gene assays of modified PutA proteins show that disrupting the FAD N(5)-Arg431 interaction impairs the reductive activation of PutA-membrane binding. We also show that the FAD 2'-OH group acts as a redox-sensitive toggle switch that controls PutA-membrane binding. These results illustrate a new versatility of the ribityl chain in flavoprotein mechanisms.
About this Structure
2FZM is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Proline dehydrogenase, with EC number 1.5.99.8 Full crystallographic information is available from OCA.
Reference
Redox-induced changes in flavin structure and roles of flavin N(5) and the ribityl 2'-OH group in regulating PutA--membrane binding., Zhang W, Zhang M, Zhu W, Zhou Y, Wanduragala S, Rewinkel D, Tanner JJ, Becker DF, Biochemistry. 2007 Jan 16;46(2):483-91. PMID:17209558
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