1j5l
From Proteopedia
NMR STRUCTURE OF THE ISOLATED BETA_C DOMAIN OF LOBSTER METALLOTHIONEIN-1
Structural highlights
FunctionMT1_HOMAM Metallothioneins have a high content of cysteine residues that bind various heavy metals. The different forms of lobster metallothioneins may have different biological functions. Class I MTS in marine crustacea are involved in the sequestration of elevated levels of heavy-metal ions. Binds 6 metal ions. Known to bind cadmium. Publication Abstract from PubMedThe three-dimensional structures of the isolated Cd(3)beta domains from Homarus americanus metallothionein have been determined by NMR methods in order to establish a set of beta-domain structures for comparative analysis. First, it was determined that the Cd-cysteine connectivities forming the Cd(3)S(9) metal center were identical to those observed for the beta(N) domain in the native holoprotein. Time- and temperature-dependence studies of the (113)Cd and (1)H 1D-NMR spectra indicated that the beta(N) domain undergoes slow conformational changes before reaching an equilibrium structure. In addition to structural information provided by the metal-to-cysteine connectivities, Phi, chi(1) and chi(2) angle constraints, three H(N...)S hydrogen bond interactions were also determined from a long-range optimized (1)H(N)-(113)Cd HMQC experiment. A simulated annealing protocol was applied to the distance and angle constraints obtained from the 2D-NMR experiments to calculate the three-dimensional structure of the synthetic Cd(3)beta(N) domain of lobster metallothionein. Structure-reactivity relationships are proposed for the reactions of Cd(3)beta domains with 5,5'-dithiobis(2-nitrobenzoate), based on comparisons of surface exposure of sulfur atoms of the lobster and rabbit Cd(3)beta domain structures. Finally, the surface exposure of the beta domains of lobster is compared with beta domains from mammalian metallothioneins. Structure of the (113)Cd(3)beta domains from Homarus americanus metallothionein-1: hydrogen bonding and solvent accessibility of sulfur atoms.,Munoz A, Forsterling FH, Shaw CF 3rd, Petering DH J Biol Inorg Chem. 2002 Sep;7(7-8):713-24. Epub 2002 Mar 13. PMID:12203008[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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