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Preliminary crystallographic analysis of the breakage-reunion domain of the Escherichia coli DNA gyrase a protein

1990; Elsevier BV; Volume: 215; Issue: 4 Linguagem: Inglês

10.1016/s0022-2836(05)80162-7

1089-8638

Richard J. Reece, Z. Dauter, Keith S. Wilson, Anthony Maxwell, Dale B. Wigley,

Biochemical and Molecular Research

The 64 × 103 Mr N-terminal breakage-reunion domain of the Escherichia coli DNA gyrase A protein was purified from an over-expressing strain. When complexed with the gyrase B protein, this truncated A protein has all of the enzymic properties of the full-length counterpart, although with reduced efficiency in some cases. The 64 × 103 Mr protein has been crystallized in several forms, a number of which were too small for crystallographic analysis. However, two forms grew to sufficient size for preliminary X-ray analysis. Both forms were tetragonal with a primitive lattice. One form (type I) had cell dimensions of a = b = 170 Å, c = 145 Å a space group of either P41212 (P43212) or P42212, and diffracted to 6 Å resolution. The type II crystals had cell dimensions of a = b = 177 Å, c = 175 Å, a space group of P41212 (P43212) or P42212, and diffracted to at least 4·5 Å resolution. Both crystal forms apparently contained four subunits (possibly a tetramer) in the asymmetric unit. We are attempting to increase the size and quality of these crystals.