title: Structure of catabolite activator protein with cobalt(II) and sulfate.
abstract: The crystal structure of cyclic AMP-catabolite activator protein (CAP) from Escherichia coli containing cobalt(II) chloride and ammonium sulfate is reported at 1.97 Å resolution. Each of the two CAP subunits in the asymmetric unit binds one cobalt(II) ion, in each case coordinated by N-terminal domain residues His19, His21 and Glu96 plus an additional acidic residue contributed via a crystal contact. The three identified N-terminal domain cobalt-binding residues are part of a region of CAP that is important for transcription activation at class II CAP-dependent promoters. Sulfate anions mediate additional crystal lattice contacts and occupy sites corresponding to DNA backbone phosphate positions in CAP-DNA complex structures.
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA.
authors.forename: Ramya R
authors.initials: RR
authors.lastname: Rao
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA.
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Lawson
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D002373:Cyclic AMP Receptor Protein / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013431:Sulfates / Q000737:chemistry*
chemical_list: D002373:Cyclic AMP Receptor Protein; D013431:Sulfates; D003035:Cobalt
keywords: Escherichia coli; catabolite activator protein