کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10795729 | 1052593 | 2014 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A hydrogen bond network in the active site of Anabaena ferredoxin-NADP+ reductase modulates its catalytic efficiency
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کلمات کلیدی
CTCflavin adenine dinucleotide5-deazariboflavinPPIDRFNMNKETFerredoxin-NADP+ reductase - Feredoxin-NADP + ردوکتازNADP+ - NADP +electron transfer - انتقال الکترونHydride transfer - انتقال هیدریدهاFAD - بدFlavoenzyme - فلاووئنزیمIonic strength - قدرت یونیCharge-transfer complex - مجموعه انتقال شارژwild-type - نوع وحشیPyrophosphate - پیرو فسفاتKIE - کیه
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش گیاه شناسی
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چکیده انگلیسی
Ferredoxin-nicotinamide-adenine dinucleotide phosphate (NADP+) reductase (FNR) catalyses the production of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) in photosynthetic organisms, where its flavin adenine dinucleotide (FAD) cofactor takes two electrons from two reduced ferredoxin (Fd) molecules in two sequential steps, and transfers them to NADP+ in a single hydride transfer (HT) step. Despite the good knowledge of this catalytic machinery, additional roles can still be envisaged for already reported key residues, and new features are added to residues not previously identified as having a particular role in the mechanism. Here, we analyse for the first time the role of Ser59 in Anabaena FNR, a residue suggested by recent theoretical simulations as putatively involved in competent binding of the coenzyme in the active site by cooperating with Ser80. We show that Ser59 indirectly modulates the geometry of the active site, the interaction with substrates and the electronic properties of the isoalloxazine ring, and in consequence the electron transfer (ET) and HT processes. Additionally, we revise the role of Tyr79 and Ser80, previously investigated in homologous enzymes from plants. Our results probe that the active site of FNR is tuned by a H-bond network that involves the side-chains of these residues and that results to critical optimal substrate binding, exchange of electrons and, particularly, competent disposition of the C4n (hydride acceptor/donor) of the nicotinamide moiety of the coenzyme during the reversible HT event.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1837, Issue 2, February 2014, Pages 251-263
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1837, Issue 2, February 2014, Pages 251-263
نویسندگان
Ana Sánchez-Azqueta, Beatriz Herguedas, Ramón Hurtado-Guerrero, Manuel Hervás, José A. Navarro, Marta MartÃnez-Júlvez, Milagros Medina,