Ferredoxins amino acid sequences

Figure 2, Amino acid sequence of Spinilina maxima ferredoxin.

Sequence comparisons may also suggest new ligands. Recently, the complete amino acid sequence for a ferredoxin from the thermophilic organism Pyrococcus furiosus was determined (Eccleston et al., 1991). All... 

Note Added in Proof. The amino acid sequence of Peplococcus aerogenes ferredoxin has been revised based upon new, high resolution X-ray diffraction studies (Backes ta/., 1991). The new numbering has an insertion after residue 25 such that the last four cysteines are one higher. 

Antitumor drugs cisplatin as, history, 37 175-179 platinum compounds future studies, 37 206-208 resistance to, 37 192-193 second-generation, 37 178 Antiviral agents, 36 37-38 AOR, see Aldehyde oxidoreductase Aphanothece sacrum, ferredoxins, amino acid sequence, 38 225-227 Apo-calcylin, 46 455 Apo-caldodulin, 46 449-450 Apoenzyme, 22 424 Apoferritin biosynthesis, 36 457 cystalline iron core, 36 423 Fe(III)distribution, 36 458-459 Fe(II) sequestration, 36 463-464 ferroxidase centers, 36 457-458 iron core reconstruction in shell, 36 457 mineralization, 36 25 Mdssbauer spectra, 36 459-460 optical absorbance spectra, 36 418-419 subunit conformation and quaternary structure, 36 470-471... 

Spirocyclophosphazene, 21 72, 109 Spiro-phosphonium hexafluorophosphate, synthesis of, 14 87 Spirophosphorane, 21 72 Spirulina ferredoxin, amino acid sequences, 38 236... 

Much of the amino acid sequence in the first half of the ferredoxin chain is repeated in the second half, suggesting that the chain may have originated as a result of gene duplication. Many invariant positions are present in the sequence, including those of the cysteine residues forming the Fe-S cluster. Ferredoxins with single Fe4S4 clusters are also known 270... 

Whereas the electron acceptors in the anaerobic organisms are the bacterial-type ferredoxins that contain [4Fe-S] clusters as the redox center, in the case of the halobacteria the electrons are transferred to [2Fe-S] ferredoxins. These ferredoxins were isolated from two different halobacteria and their amino acid sequences were determined (Hase et al., 1977, 1980) and shown to be highly homologous to the chloroplast (and cyanobacterial) ferredoxins. The implications of these perplexing findings for the question of the molecular evolution of the system is discussed in detail in Kerscher and Oesterhelt (1982). 

As was pointed out previously, clostridial ferredoxins are closely related in spectral properties, iron, and inorganic sulfide content, and amino acid composition. The recent work of Tanaka et al. (100) shows that this similarity applies also to the amino acid sequence of these proteins. Preliminary results indicated that C. butyricum ferredoxin, like C. pasteurianum, contains 55 amino acid residues (3 in addition to those in Table 6), the same glutaminyl-glutamic acid carboxyl-terminal sequence, and the same aminoterminal amino acid, alanine. Their results show also the isomorphic replacement of certain amino acids, such as phenylalanine for tyrosine. 

The amino acid sequence in the ferredoxins is quite distinctive the position of the cysteines which bind the irons in a specific environment do not vary in different classes of ferredoxins this is shown in Figure 6,... 

Figure 6. Amino acid sequences of representative ferredoxins. A, Clostridium butyricum (8Fe) obligate anaerobic fermenting bacterium B, (8Fe) red (sulfur) photosynthetic bacterium D, Desulfovibrio gigas (4Fe) sulfate...

T. Nakashima, A. Benson, H. F. Mower, and K. T. Yasunobu The amino acid sequence of Clostridium pasteurianum ferredoxin. Biochem. Biophys. Res. Commun. 16, 422 (1964). 

The amino acid sequence of Clostridium pasteurianum ferredoxin. 

Structural data on the organization of the active clusters and the various subunits can be obtained from biochemical, biophysical and genetic studies. However, the final word is in the mouth of the crystallographer, after the biochemist hands him the crystals. Only one piece of solid information is available to date, and this is the amino acid sequences of subunits la and Ib [78,79]. These two subunits should accommodate the P-700, the primary electron acceptor (Ai), and probably the secondary electron acceptor A2 which is the nonheme iron cluster X. The amino acid sequences of subunits I and I, make it unlikely that these subunits also contain one of the bound ferredoxins A or B because subunit I, contains 4 cysteine residues and subunit I, contains only 2 cysteines [79]. These numbers are hardly sufficient for the formation of the nonheme iron cluster X which is supposed to be a nonheme iron center [74,88]. Therefore, it may be likely that sub-... 

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