Unique features of iron storage in EcFtna

In EcFtna a relaxation spectrum c has been assigned mainly to mononuclear Fe(III) at site C, although the possibility that part of this spectrum is due to small clusters with an uneven number of Fe(III) atoms (e.g. trimers or pentamers) cannot be ruled out. In contrast, the Fe(III) relaxation spectrum observed in HuHF seems to be due mainly to iron ligated to aspartate and glutamates in the three-fold intersubunit channels [68]. Such iron would not be expected in EcFtna because carbox-ylates are absent from its three-fold channels [5]. 

H-type ferritins belong to the class II diiron proteins that also comprises RNR R2 and MMOH subunits, ACP-stearoyl-desaturase and rubrerythrin. Interaction of 

We thank the Wellcome Trust for financial support and Dr. S. C. Andrews, Prof. E. R. Bauminger, Dr. P. D. Hempstead, Dr. M. A. Quail, Dr. T. J. Stillman, Dr. Z. Zhao for kindly providing unpublished data, materials or illustrations. 

Precigoux in International Symposium Iron in Biology and Medicine, Saint-Malo, France, 1997, 87. 

Note added in proof recent high resolution X-ray analysis of iron derivatives of EcFtna crystals show that Gla 130 ligates both side B and site C Fe atoms forming a bridge between them rather than alternating as a ligand of either site as described on p 231 and depicted in Fig. 15-4. 

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