1CEI

STRUCTURE DETERMINATION OF THE COLICIN E7 IMMUNITY PROTEIN (IMME7) THAT BINDS SPECIFICALLY TO THE DNASE-TYPE COLICIN E7 AND INHIBITS ITS BACTERIOCIDAL ACTIVITY

Summary for 1CEI

• Entry DOI: 10.2210/pdb1cei/pdb
• Descriptor: COLICIN E7 IMMUNITY PROTEIN (2 entities in total)
• Functional Keywords: immunity protein, antibacterial protein
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 10651.85

Authors

Chak, K.-F.,Safo, M.K.,Ku, W.-Y.,Hsieh, S.-Y.,Yuan, H.S. (deposition date: 1996-03-19, release date: 1997-03-12, Last modification date: 2024-02-07)

Primary citation

Chak, K.F.,Safo, M.K.,Ku, W.Y.,Hsieh, S.Y.,Yuan, H.S.
The crystal structure of the immunity protein of colicin E7 suggests a possible colicin-interacting surface.
Proc.Natl.Acad.Sci.USA, 93:6437-6442, 1996

PubMed Abstract: The immunity protein of colicin E7 (ImmE7) can bind specifically to the DNase-type colicin E7 and inhibit its bactericidal activity. Here we report the 1.8-angstrom crystal structure of the ImmE7 protein. This is the first x-ray structure determined in the superfamily of colicin immunity proteins. The ImmE7 protein consists of four antiparallel alpha-helices, folded in a topology similar to the architecture of a four-helix bundle structure. A region rich in acidic residues is identified. This negatively charged area has the greatest variability within the family of DNase-type immunity proteins; thus, it seems likely that this area is involved in specific binding to colicin. Based on structural, genetic, and kinetic data, we suggest that all the DNase-type immunity proteins, as well as colicins, share a "homologous-structural framework" and that specific interaction between a colicin and its cognate immunity protein relies upon how well these two proteins' charged residues match on the interaction surface, thus leading to specific immunity of the colicin.

PubMed: 8692833
DOI: 10.1073/pnas.93.13.6437

Experimental method

X-RAY DIFFRACTION (1.8 Å)