Common metal ion coordination in LIM domain proteins

作者：Jessica Lang Kosa, James W. Michelsen, Heather A. Louis, Jay I. Olsen, Darrell R. Davis, Mary C. Beckerle, Dennis R. Winge · 发表于：Biochemistry · 年份：1994 · DOI：10.1021/bi00168a011 · 被引用次数：88 · 研究领域：Magnesium Alloys: Properties and Applications、Studies on Chitinases and Chitosanases、Peptidase Inhibition and Analysis

The LIM motif is a cysteine- and histidine-rich sequence that was first identified in proteins involved in control of gene expression and cell differentiation. In order to characterize structural features of the LIM domain, we have carried out biophysical studies on two polypeptides that display LIM domains: the cysteine-rich intestinal protein (CRIP) and a fragment of the cysteine-rich protein (CRP). Bacterial expression vectors were constructed for the intact CRIP molecule and the C-terminal half of CRP, designated LIM2, such that each expressed protein contained a single LIM domain. Both proteins were recovered as soluble, Zn(II)-containing proteins. The metal coordination properties of these two distinct LIM domain proteins were highly similar, suggesting that a common structural architecture may exist in LIM domain proteins. Both proteins exhibit a maximum of two tetrahedrally bound Zn(II) ions per molecule. Electronic spectroscopy of Co(II) complexes and 113Cd NMR of Cd(II) complexes of CRIP and LIM2 revealed a similar ligand field pattern with one tetrathiolate (S4) site and one S3N1 site for divalent metal ions. The nitrogen ligand was shown to arise from a histidyl imidazole by heteronuclear multiple quantum coherence NMR. The eight conserved residues within the LIM domains of CRIP and LIM2 include seven cysteines and one histidine. It is likely that these conserved residues generate the S4 and S3N1 Zn(II)-binding sites. Metal binding to the two sites within a single...