Crystallization and structure at 3.2 Å resolution of a terbium parvalbumin

AbstractToadfish muscle parvalbumin IIIf can bind two Tb3+ which displace the two Ca2+ normally bound. This terbium derivative was crystallized with space group P21212 and lattice constants a = 56.2 Å, b = 59.5 Å and c = 27.2 Å. The structure at 3.2 Å resolution was determined applying a molecular replacement method and using the known co-ordinates of carp Ca2+-parvalbumin. The structure was refined to a conventional R factor of 26% for 1166 reflections in the resolution range 3.2–6 Å. The α-carbon backbone of the structures of toadfish and carp parvalbumins are very similar.CrystalX-ray crystallographyThree-dimensional structureTb3+ParvalbuminCa2+-binding sit