2g18
From Proteopedia
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'''Crystal Structure of Nostoc sp. 7120 phycocyanobilin:ferredoxin oxidoreductase (PcyA) Apoprotein''' | '''Crystal Structure of Nostoc sp. 7120 phycocyanobilin:ferredoxin oxidoreductase (PcyA) Apoprotein''' | ||
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| + | ==Overview== | ||
| + | The X-ray crystal structure of the substrate-free form of phycocyanobilin (PCB)-ferredoxin oxidoreductase (PcyA; EC 1.3.7.5) from the cyanobacterium Nostoc sp. PCC7120 has been solved at 2.5 A resolution. A comparative analysis of this structure with those recently reported for substrate-bound and substrate-free forms of PcyA from the cyanobacterium Synechocystis sp. PCC6803 (Hagiwara et al. (2006) Proc. Natl. Acad. Sci. U.S.A. 103, 27-32; Hagiwara et al. (2006) FEBS Lett. 580, 3823-3828) provides a compelling picture of substrate-induced changes in the PcyA enzyme and the chemical basis of PcyA's catalytic activity. On the basis of these structures and the biochemical analysis of site-directed mutants of Nostoc PcyA, including mutants reported in recent studies (Tu et al. (2006) J. Biol. Chem. 281, 3127-3136) as well as mutants described in this study, a revised mechanism for the PcyA-mediated four-electron reduction of biliverdin IXalpha to 3E/3Z-phycocyanobilin via enzyme-bound bilin radical intermediates is proposed. The mechanistic insight of these studies, along with homology modeling, have provided new insight into the catalytic mechanisms of other members of the ferredoxin-dependent bilin reductase family that are widespread in oxygenic photosynthetic organisms. | ||
==About this Structure== | ==About this Structure== | ||
2G18 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Anabaena_sp. Anabaena sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2G18 OCA]. | 2G18 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Anabaena_sp. Anabaena sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2G18 OCA]. | ||
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| + | ==Reference== | ||
| + | Insight into the radical mechanism of phycocyanobilin-ferredoxin oxidoreductase (PcyA) revealed by X-ray crystallography and biochemical measurements., Tu SL, Rockwell NC, Lagarias JC, Fisher AJ, Biochemistry. 2007 Feb 13;46(6):1484-94. Epub 2007 Jan 17. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17279614 17279614] | ||
[[Category: Anabaena sp.]] | [[Category: Anabaena sp.]] | ||
[[Category: Phycocyanobilin:ferredoxin oxidoreductase]] | [[Category: Phycocyanobilin:ferredoxin oxidoreductase]] | ||
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[[Category: Tu, S L.]] | [[Category: Tu, S L.]] | ||
[[Category: Alpha-beta-alpha sandwich]] | [[Category: Alpha-beta-alpha sandwich]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | [[Category: Oxidoreductase]] |
| + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu May 22 22:22:55 2008'' | ||
Revision as of 19:22, 22 May 2008
Crystal Structure of Nostoc sp. 7120 phycocyanobilin:ferredoxin oxidoreductase (PcyA) Apoprotein
Overview
The X-ray crystal structure of the substrate-free form of phycocyanobilin (PCB)-ferredoxin oxidoreductase (PcyA; EC 1.3.7.5) from the cyanobacterium Nostoc sp. PCC7120 has been solved at 2.5 A resolution. A comparative analysis of this structure with those recently reported for substrate-bound and substrate-free forms of PcyA from the cyanobacterium Synechocystis sp. PCC6803 (Hagiwara et al. (2006) Proc. Natl. Acad. Sci. U.S.A. 103, 27-32; Hagiwara et al. (2006) FEBS Lett. 580, 3823-3828) provides a compelling picture of substrate-induced changes in the PcyA enzyme and the chemical basis of PcyA's catalytic activity. On the basis of these structures and the biochemical analysis of site-directed mutants of Nostoc PcyA, including mutants reported in recent studies (Tu et al. (2006) J. Biol. Chem. 281, 3127-3136) as well as mutants described in this study, a revised mechanism for the PcyA-mediated four-electron reduction of biliverdin IXalpha to 3E/3Z-phycocyanobilin via enzyme-bound bilin radical intermediates is proposed. The mechanistic insight of these studies, along with homology modeling, have provided new insight into the catalytic mechanisms of other members of the ferredoxin-dependent bilin reductase family that are widespread in oxygenic photosynthetic organisms.
About this Structure
2G18 is a Single protein structure of sequence from Anabaena sp.. Full crystallographic information is available from OCA.
Reference
Insight into the radical mechanism of phycocyanobilin-ferredoxin oxidoreductase (PcyA) revealed by X-ray crystallography and biochemical measurements., Tu SL, Rockwell NC, Lagarias JC, Fisher AJ, Biochemistry. 2007 Feb 13;46(6):1484-94. Epub 2007 Jan 17. PMID:17279614 Page seeded by OCA on Thu May 22 22:22:55 2008
