Preliminary X-ray crystallographic analysis of the complex between the DNAase domain of colicin E9 and its cognate immunity protein

Ulrike C. Kühlmann, Colin Kleanthous, Richard James, Geoffrey R. Moore, Andrew M. Hemmings

Research output: Contribution to journalArticlepeer-review

Abstract

We have crystallized and performed preliminary X-ray characterization of the complex between the DNAase domain of the E9 colicin and its cognate immunity protein Im9. The dissociation constant for this complex, K(d) = 1 x 10-16 M, reveals it to be one of the highest affinity protein-protein interactions known. Single crystals of the 1:1 complex were grown from microseeding experiments using PEG 4K as precipitant. The space group is P212121 with one molecule of complex in the asymmetric unit, and crystals contain approximately 43% solvent. These crystals are inherently non-isomorphous and so selenomethionine-derivatized protein has been prepared and crystals grown for MAD phasing experiments.

Original languageEnglish
Pages (from-to)256-259
Number of pages4
JournalActa Crystallographica Section D: Biological Crystallography
Volume55
Issue number1
DOIs
Publication statusPublished - 1 Jan 1999

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