An NMR Study of the 7Fe-8S Ferredoxin from Rhodopseudomonas palustris and Reinterpretation of Data on Similar Systems
详细信息 查看全文
- 作者：Ivano Bertini ; Alexander Dikiy ; Claudio Luchinat ; Riccardo Macinai ; Maria Silvia Viezzoli ; and Massimo Vincenzini
- 刊名：Biochemistry
- 出版年：1997
- 出版时间：March 25, 1997
- 年：1997
- 卷：36
- 期：12
- 页码：3570 - 3579
- 全文大小：207K
- 年卷期：v.36,no.12(March 25, 1997)
- ISSN：1520-4995
文摘
The oxidized 7Fe-8S ferredoxin fromRhodopseudomonas palustris is shown to possessaunique 1H NMR spectrum displaying at least onehyperfine-shifted 
-CH2 signal for each cysteineboundto the [3Fe-4S] cluster. COSY and TOCSY spectra and 1- and2-dimensional NOE experiments, inconjunction with a thorough reexamination of the 1H NMRdata on similar systems, permitted the sequentialassignment of all of the cysteine -CH2 protons even inthe absence of the amino acid sequence. Thesequential assignment stems on the homology of the hyperfine shiftpattern with those of other sequenced7Fe-8S ferredoxins, which points to a substantial homology in tertiarystructure. From the assignment,an analysis of the antiferromagnetic coupling in the [3Fe-4S] systemwas performed on the basis of ageneral model of exchange coupling. The NMR signal patterns of[3Fe-4S] clusters in both 3Fe-4S and7Fe-8S ferredoxins have been discussed, and some correlations areproposed between signal patterns andthe primary sequence.
-CH2 signal for each cysteineboundto the [3Fe-4S] cluster. COSY and TOCSY spectra and 1- and2-dimensional NOE experiments, inconjunction with a thorough reexamination of the 1H NMRdata on similar systems, permitted the sequentialassignment of all of the cysteine -CH2 protons even inthe absence of the amino acid sequence. Thesequential assignment stems on the homology of the hyperfine shiftpattern with those of other sequenced7Fe-8S ferredoxins, which points to a substantial homology in tertiarystructure. From the assignment,an analysis of the antiferromagnetic coupling in the [3Fe-4S] systemwas performed on the basis of ageneral model of exchange coupling. The NMR signal patterns of[3Fe-4S] clusters in both 3Fe-4S and7Fe-8S ferredoxins have been discussed, and some correlations areproposed between signal patterns andthe primary sequence.