1jb9
From Proteopedia
Crystal Structure of The Ferredoxin:NADP+ Reductase From Maize Root AT 1.7 Angstroms
Overview
Distinct forms of ferredoxin-NADP(+) reductase are expressed in photosynthetic and nonphotosynthetic plant tissues. Both enzymes catalyze electron transfer between NADP(H) and ferredoxin; whereas in leaves the enzyme transfers reducing equivalents from photoreduced ferredoxin to NADP(+) in photosynthesis, in roots it has the opposite physiological role, reducing ferredoxin at the expense of NADPH mainly for use in nitrate assimilation. Here, structural and kinetic properties of a nonphotosynthetic isoform were analyzed to define characteristics that may be related to tissue-specific function. Compared with spinach leaf ferredoxin-NADP(+) reductase, the recombinant corn root isoform showed a slightly altered absorption spectrum, a higher pI, a >30-fold higher affinity for NADP(+), greater susceptibility to limited proteolysis, and an approximately 20 mV more positive redox potential. The 1.7 A resolution crystal structure is very similar to the structures of ferredoxin-NADP(+) reductases from photosynthetic tissues. Four distinct structural features of this root ferredoxin-NADP(+) reductases are an alternate conformation of the bound FAD molecule, an alternate path for the amino-terminal extension, a disulfide bond in the FAD-binding domain, and changes in the surface that binds ferredoxin.
About this Structure
1JB9 is a Single protein structure of sequence from Zea mays. Full crystallographic information is available from OCA.
Reference
Biochemical and crystallographic characterization of ferredoxin-NADP(+) reductase from nonphotosynthetic tissues., Aliverti A, Faber R, Finnerty CM, Ferioli C, Pandini V, Negri A, Karplus PA, Zanetti G, Biochemistry. 2001 Dec 4;40(48):14501-8. PMID:11724563 Page seeded by OCA on Fri May 2 21:00:30 2008
