Open AccessCrystallization and preliminary X‐ray diffraction data for the aconitase form of human iron‐regulatory protein 1
Author(s) -
Dupuy J.,
Darnault C.,
Moulis J. M.,
Brazzolotto X.,
Kühn L. C.,
Volbeda A.,
FontecillaCamps J. C.
Publication year - 2005
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309105010444
Subject(s) - aconitase , crystallization , chemistry , cytoplasm , zinc , crystallography , metabolism , biochemistry , biophysics , mitochondrion , biology , organic chemistry
Iron‐regulatory proteins (IRPs) 1 and 2 are closely related molecules involved in animal iron metabolism. Both proteins can bind to specific mRNA regions called iron‐responsive elements and thereby control the expression of proteins involved in the uptake, storage and utilization of iron. In iron‐replete cells, IRP1, but not IRP2, binds a [4Fe–4S] cluster and functions as a cytoplasmic aconitase, with simultaneous loss of its RNA‐binding ability. Whereas IRP2 is known to be involved in Fe homeostasis, the role of IRP1 is less clear; it may provide a link between citrate and iron metabolisms and be involved in oxidative stress response. Here, two crystal forms of the aconitase version of recombinant human IRP1 are reported. An X‐ray fluorescence measurement performed on a gold‐derivative crystal showed the unexpected presence of zinc, in addition to gold and iron. Both native and MAD X‐ray data at the Au, Fe and Zn absorption edges have been collected from these crystals.