2I99

Crystal structure of human Mu_crystallin at 2.6 Angstrom

Summary for 2I99

• Entry DOI: 10.2210/pdb2i99/pdb
• Descriptor: Mu-crystallin homolog, NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE (3 entities in total)
• Functional Keywords: mu_crystallin, thyroid hormine binding protein, oxidoreductase
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 2
• Total formula weight: 68589.03

Authors

Cheng, Z.,Sun, L.,He, J.,Gong, W. (deposition date: 2006-09-05, release date: 2007-02-27, Last modification date: 2023-10-25)

Primary citation

Cheng, Z.,Sun, L.,He, J.,Gong, W.
Crystal structure of human {micro}-crystallin complexed with NADPH
Protein Sci., 16:329-335, 2007

PubMed Abstract: Human cytosolic 3,5,3'-triiodo-L-thyronine-binding protein, also called mu-crystallin or CRYM, plays important physiological roles in transporting 3,5,3'-triiodo-L-thyronine (T(3)) into nuclei and regulating thyroid-hormone-related gene expression. The crystal structure of human CRYM's bacterial homolog Pseudomonas putida ornithine cyclodeaminase and Archaeoglobus fulgidus alanine dehydrogenase have been available, but no CRYM structure has been reported. Here, we report the crystal structure of human CRYM bound with NADPH refined to 2.6 A, and there is one dimer in the asymmetric unit. The structure contains two domains: a Rossmann fold-like NADPH-binding domain and a dimerization domain. Different conformations of the loop Arg83-His92 have been observed in two monomers of human CRYM in the same asymmetric unit. The peptide bond of Val89-Pro90 is a trans-configuration in one monomer but a cis-configuration in the other. A detailed comparison of the human mu-crystallin structure with its structurally characterized homologs including the overall comparison and superposition of active sites was conducted. Finally, a putative T(3)-binding site in human CRYM is proposed based on comparison with structural homologs.

PubMed: 17242435
DOI: 10.1110/ps.062556907

Experimental method

X-RAY DIFFRACTION (2.6 Å)