ISSN:
1399-0047
Quelle:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Thema:
Chemie und Pharmazie
,
Geologie und Paläontologie
,
Physik
Notizen:
The metal cluster Ta6Br14 has been used to prepare heavy-metal derivatives of two large proteins, ribulose-1,5-bisphosphate carboxylase/oxygenase and transketolase. In both cases, this cluster compound produced a single-site derivative for which a difference Patterson map, calculated to 5.5 Å resolution, could be solved straightforwardly. Ta6Br14 provided enough phase information to unambiguously locate the heavy-atom positions in other multiple-site derivatives. In transketolase, the heavy-metal complex binds at the surface of the protein in a dominantly hydrophobic pocket. In ribulose bisphosphate carboxylase/oxygenase, it binds between two molecules in the crystal lattice. There are negatively charged glutamic and/or aspartic acid residues in the vicinity of the bound clusters. Ta6Br14 is useful over a wide range of pH. For large proteins and/or large unit cells, this compound should be included in the initial screening for heavy-metal derivatives.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1107/S0907444993009679
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