View source for 1gr1

[[Image:1gr1.jpg|left|200px]]<br /><applet load="1gr1" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="1gr1, resolution 2.5&Aring;" />
'''STRUCTURE OF FERREDOXIN-NADP+ REDUCTASE WITH GLU 139 REPLACED BY LYS (E139K)'''<br />

==Overview==
The role of the negative charge of the E139 side-chain of Anabaena Ferredoxin-NADP+ reductase (FNR) in steering appropriate docking with its substrates ferredoxin, flavodoxin and NADP+/H, that leads to efficient electron transfer (ET) is analysed by characterization of several E139 FNR mutants. Replacement of E139 affects the interaction with the different FNR substrates in very different ways. Thus, while E139 does not appear to be involved in the processes of binding and ET between FNR and NADP+/H, the nature and the conformation of the residue at position 139 of Anabaena FNR modulates the precise enzyme interaction with the protein carriers ferredoxin (Fd) and flavodoxin (Fld). Introduction of the shorter aspartic acid side-chain at position 139 produces an enzyme that interacts more weakly with both ET proteins. Moreover, the removal of the charge, as in the E139Q mutant, or the charge-reversal mutation, as in E139K FNR, apparently enhances additional interaction modes of the enzyme with Fd, and reduces the possible orientations with Fld to more productive and stronger ones. Hence, removal of the negative charge at position 139 of Anabaena FNR produces a deleterious effect in its ET reactions with Fd whereas it appears to enhance the ET processes with Fld. Significantly, a large structural variation is observed for the E139 side-chain conformer in different FNR structures, including the E139K mutant. In this case, a positive potential region replaces a negative one in the wild-type enzyme. Our observations further confirm the contribution of both attractive and repulsive interactions in achieving the optimal orientation for efficient ET between FNR and its protein carriers.

==About this Structure==
1GR1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Anabaena_sp. Anabaena sp.] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=FAD:'>FAD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ferredoxin--NADP(+)_reductase Ferredoxin--NADP(+) reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.18.1.2 1.18.1.2] Known structural/functional Site: <scene name='pdbsite=FAD:Fad+Binding+Site+For+Chain+A'>FAD</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GR1 OCA]. 

==Reference==
Probing the role of glutamic acid 139 of Anabaena ferredoxin-NADP+ reductase in the interaction with substrates., Faro M, Frago S, Mayoral T, Hermoso JA, Sanz-Aparicio J, Gomez-Moreno C, Medina M, Eur J Biochem. 2002 Oct;269(20):4938-47. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12383252 12383252]
[[Category: Anabaena sp.]]
[[Category: Ferredoxin--NADP(+) reductase]]
[[Category: Single protein]]
[[Category: Gomez-Moreno, C.]]
[[Category: Hermoso, J A.]]
[[Category: Mayoral, T.]]
[[Category: Medina, M.]]
[[Category: Sanz-Aparicio, J.]]
[[Category: FAD]]
[[Category: SO4]]
[[Category: fad]]
[[Category: flavoprotein]]
[[Category: fnr]]
[[Category: nadp+ reductase]]
[[Category: oxidoreductase]]

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